/* jQuery UI Date Picker v3.4.3 (previously jQuery Calendar)
   Written by Marc Grabanski (m@marcgrabanski.com) and Keith Wood (kbwood@virginbroadband.com.au).

   Copyright (c) 2007 Marc Grabanski (http://marcgrabanski.com/code/ui-datepicker)
   Dual licensed under the MIT (MIT-LICENSE.txt)
   and GPL (GPL-LICENSE.txt) licenses.
   Date: 09-03-2007  */
   
;(function($) { // hide the namespace

/* Date picker manager.
   Use the singleton instance of this class, $.datepicker, to interact with the date picker.
   Settings for (groups of) date pickers are maintained in an instance object
   (DatepickerInstance), allowing multiple different settings on the same page. */

function Datepicker() {
    this.debug = false; // Change this to true to start debugging
    this._nextId = 0; // Next ID for a date picker instance
    this._inst = []; // List of instances indexed by ID
    this._curInst = null; // The current instance in use
    this._disabledInputs = []; // List of date picker inputs that have been disabled
    this._datepickerShowing = false; // True if the popup picker is showing , false if not
    this._inDialog = false; // True if showing within a "dialog", false if not
    this.regional = []; // Available regional settings, indexed by language code
    this.regional[''] = { // Default regional settings
        clearText: 'Clear', // Display text for clear link
        clearStatus: 'Erase the current date', // Status text for clear link
        closeText: 'Close', // Display text for close link
        closeStatus: 'Close without change', // Status text for close link
        prevText: '<Prev', // Display text for previous month link
        prevStatus: 'Show the previous month', // Status text for previous month link
        nextText: 'Next>', // Display text for next month link
        nextStatus: 'Show the next month', // Status text for next month link
        currentText: 'Today', // Display text for current month link
        currentStatus: 'Show the current month', // Status text for current month link
        monthNames: ['January','February','March','April','May','June',
            'July','August','September','October','November','December'], // Names of months for drop-down and formatting
        monthNamesShort: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'], // For formatting
        monthStatus: 'Show a different month', // Status text for selecting a month
        yearStatus: 'Show a different year', // Status text for selecting a year
        weekHeader: 'Wk', // Header for the week of the year column
        weekStatus: 'Week of the year', // Status text for the week of the year column
        dayNames: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'], // For formatting
        dayNamesShort: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'], // For formatting
        dayNamesMin: ['Su','Mo','Tu','We','Th','Fr','Sa'], // Column headings for days starting at Sunday
        dayStatus: 'Set DD as first week day', // Status text for the day of the week selection
        dateStatus: 'Select DD, M d', // Status text for the date selection
        dateFormat: 'mm/dd/yy', // See format options on parseDate
        firstDay: 0, // The first day of the week, Sun = 0, Mon = 1, ...
        initStatus: 'Select a date', // Initial Status text on opening
        isRTL: false // True if right-to-left language, false if left-to-right
    };
    this._defaults = { // Global defaults for all the date picker instances
        showOn: 'focus', // 'focus' for popup on focus,
            // 'button' for trigger button, or 'both' for either
        showAnim: 'show', // Name of jQuery animation for popup
        defaultDate: null, // Used when field is blank: actual date,
            // +/-number for offset from today, null for today
        appendText: '', // Display text following the input box, e.g. showing the format
        buttonText: '...', // Text for trigger button
        buttonImage: '', // URL for trigger button image
        buttonImageOnly: false, // True if the image appears alone, false if it appears on a button
        closeAtTop: true, // True to have the clear/close at the top,
            // false to have them at the bottom
        mandatory: false, // True to hide the Clear link, false to include it
        hideIfNoPrevNext: false, // True to hide next/previous month links
            // if not applicable, false to just disable them
        changeMonth: true, // True if month can be selected directly, false if only prev/next
        changeYear: true, // True if year can be selected directly, false if only prev/next
        yearRange: '-10:+10', // Range of years to display in drop-down,
            // either relative to current year (-nn:+nn) or absolute (nnnn:nnnn)
        changeFirstDay: true, // True to click on day name to change, false to remain as set
        showOtherMonths: false, // True to show dates in other months, false to leave blank
        showWeeks: false, // True to show week of the year, false to omit
        calculateWeek: this.iso8601Week, // How to calculate the week of the year,
            // takes a Date and returns the number of the week for it
        shortYearCutoff: '+10', // Short year values < this are in the current century,
            // > this are in the previous century, 
            // string value starting with '+' for current year + value
        showStatus: false, // True to show status bar at bottom, false to not show it
        statusForDate: this.dateStatus, // Function to provide status text for a date -
            // takes date and instance as parameters, returns display text
        minDate: null, // The earliest selectable date, or null for no limit
        maxDate: null, // The latest selectable date, or null for no limit
        speed: 'normal', // Speed of display/closure
        beforeShowDay: null, // Function that takes a date and returns an array with
            // [0] = true if selectable, false if not,
            // [1] = custom CSS class name(s) or '', e.g. $.datepicker.noWeekends
        beforeShow: null, // Function that takes an input field and
            // returns a set of custom settings for the date picker
        onSelect: null, // Define a callback function when a date is selected
        onClose: null, // Define a callback function when the datepicker is closed
        numberOfMonths: 1, // Number of months to show at a time
        stepMonths: 1, // Number of months to step back/forward
        rangeSelect: false, // Allows for selecting a date range on one date picker
        rangeSeparator: ' - ' // Text between two dates in a range
    };
    $.extend(this._defaults, this.regional['']);
    this._datepickerDiv = $('<div id="datepicker_div">');
}

$.extend(Datepicker.prototype, {
    /* Class name added to elements to indicate already configured with a date picker. */
    markerClassName: 'hasDatepicker',

    /* Debug logging (if enabled). */
    log: function () {
        if (this.debug)
            console.log.apply('', arguments);
    },
    
    /* Register a new date picker instance - with custom settings. */
    _register: function(inst) {
        var id = this._nextId++;
        this._inst[id] = inst;
        return id;
    },

    /* Retrieve a particular date picker instance based on its ID. */
    _getInst: function(id) {
        return this._inst[id] || id;
    },

    /* Override the default settings for all instances of the date picker. 
       @param  settings  object - the new settings to use as defaults (anonymous object)
       @return the manager object */
    setDefaults: function(settings) {
        extendRemove(this._defaults, settings || {});
        return this;
    },

    /* Attach the date picker to a jQuery selection.
       @param  target    element - the target input field or division or span
       @param  settings  object - the new settings to use for this date picker instance (anonymous) */
    _attachDatepicker: function(target, settings) {
        // check for settings on the control itself - in namespace 'date:'
        var inlineSettings = null;
        for (attrName in this._defaults) {
            var attrValue = target.getAttribute('date:' + attrName);
            if (attrValue) {
                inlineSettings = inlineSettings || {};
                try {
                    inlineSettings[attrName] = eval(attrValue);
                } catch (err) {
                    inlineSettings[attrName] = attrValue;
                }
            }
        }
        var nodeName = target.nodeName.toLowerCase();
        var instSettings = (inlineSettings ? 
            $.extend(settings || {}, inlineSettings || {}) : settings);
        if (nodeName == 'input') {
            var inst = (inst && !inlineSettings ? inst :
                new DatepickerInstance(instSettings, false));
            this._connectDatepicker(target, inst);
        } else if (nodeName == 'div' || nodeName == 'span') {
            var inst = new DatepickerInstance(instSettings, true);
            this._inlineDatepicker(target, inst);
        }
    },

    /* Detach a datepicker from its control.
       @param  target    element - the target input field or division or span */
    _destroyDatepicker: function(target) {
        var nodeName = target.nodeName.toLowerCase();
        var calId = target._calId;
        target._calId = null;
        var $target = $(target);
        if (nodeName == 'input') {
            $target.siblings('.datepicker_append').replaceWith('').end()
                .siblings('.datepicker_trigger').replaceWith('').end()
                .removeClass(this.markerClassName)
                .unbind('focus', this._showDatepicker)
                .unbind('keydown', this._doKeyDown)
                .unbind('keypress', this._doKeyPress);
            var wrapper = $target.parents('.datepicker_wrap');
            if (wrapper)
                wrapper.replaceWith(wrapper.html());
        } else if (nodeName == 'div' || nodeName == 'span')
            $target.removeClass(this.markerClassName).empty();
        if ($('input[_calId=' + calId + ']').length == 0)
            // clean up if last for this ID
            this._inst[calId] = null;
    },

    /* Enable the date picker to a jQuery selection.
       @param  target    element - the target input field or division or span */
    _enableDatepicker: function(target) {
        target.disabled = false;
        $(target).siblings('button.datepicker_trigger').each(function() { this.disabled = false; }).end()
            .siblings('img.datepicker_trigger').css({opacity: '1.0', cursor: ''});
        this._disabledInputs = $.map(this._disabledInputs,
            function(value) { return (value == target ? null : value); }); // delete entry
    },

    /* Disable the date picker to a jQuery selection.
       @param  target    element - the target input field or division or span */
    _disableDatepicker: function(target) {
        target.disabled = true;
        $(target).siblings('button.datepicker_trigger').each(function() { this.disabled = true; }).end()
            .siblings('img.datepicker_trigger').css({opacity: '0.5', cursor: 'default'});
        this._disabledInputs = $.map($.datepicker._disabledInputs,
            function(value) { return (value == target ? null : value); }); // delete entry
        this._disabledInputs[$.datepicker._disabledInputs.length] = target;
    },

    /* Is the first field in a jQuery collection disabled as a datepicker?
       @param  target    element - the target input field or division or span
       @return boolean - true if disabled, false if enabled */
    _isDisabledDatepicker: function(target) {
        if (!target)
            return false;
        for (var i = 0; i < this._disabledInputs.length; i++) {
            if (this._disabledInputs[i] == target)
                return true;
        }
        return false;
    },

    /* Update the settings for a date picker attached to an input field or division.
       @param  target  element - the target input field or division or span
       @param  name    string - the name of the setting to change or
                       object - the new settings to update
       @param  value   any - the new value for the setting (omit if above is an object) */
    _changeDatepicker: function(target, name, value) {
        var settings = name || {};
        if (typeof name == 'string') {
            settings = {};
            settings[name] = value;
        }
        if (inst = this._getInst(target._calId)) {
            extendRemove(inst._settings, settings);
            this._updateDatepicker(inst);
        }
    },

    /* Set the dates for a jQuery selection.
       @param  target   element - the target input field or division or span
       @param  date     Date - the new date
       @param  endDate  Date - the new end date for a range (optional) */
    _setDateDatepicker: function(target, date, endDate) {
        if (inst = this._getInst(target._calId)) {
            inst._setDate(date, endDate);
            this._updateDatepicker(inst);
        }
    },

    /* Get the date(s) for the first entry in a jQuery selection.
       @param  target  element - the target input field or division or span
       @return Date - the current date or
               Date[2] - the current dates for a range */
    _getDateDatepicker: function(target) {
        var inst = this._getInst(target._calId);
        return (inst ? inst._getDate() : null);
    },

    /* Handle keystrokes. */
    _doKeyDown: function(e) {
        var inst = $.datepicker._getInst(this._calId);
        if ($.datepicker._datepickerShowing)
            switch (e.keyCode) {
                case 9:  $.datepicker._hideDatepicker(null, '');
                        break; // hide on tab out
                case 13: $.datepicker._selectDay(inst, inst._selectedMonth, inst._selectedYear,
                            $('td.datepicker_daysCellOver', inst._datepickerDiv)[0]);
                        return false; // don't submit the form
                        break; // select the value on enter
                case 27: $.datepicker._hideDatepicker(null, inst._get('speed'));
                        break; // hide on escape
                case 33: $.datepicker._adjustDate(inst,
                            (e.ctrlKey ? -1 : -inst._get('stepMonths')), (e.ctrlKey ? 'Y' : 'M'));
                        break; // previous month/year on page up/+ ctrl
                case 34: $.datepicker._adjustDate(inst,
                            (e.ctrlKey ? +1 : +inst._get('stepMonths')), (e.ctrlKey ? 'Y' : 'M'));
                        break; // next month/year on page down/+ ctrl
                case 35: if (e.ctrlKey) $.datepicker._clearDate(inst);
                        break; // clear on ctrl+end
                case 36: if (e.ctrlKey) $.datepicker._gotoToday(inst);
                        break; // current on ctrl+home
                case 37: if (e.ctrlKey) $.datepicker._adjustDate(inst, -1, 'D');
                        break; // -1 day on ctrl+left
                case 38: if (e.ctrlKey) $.datepicker._adjustDate(inst, -7, 'D');
                        break; // -1 week on ctrl+up
                case 39: if (e.ctrlKey) $.datepicker._adjustDate(inst, +1, 'D');
                        break; // +1 day on ctrl+right
                case 40: if (e.ctrlKey) $.datepicker._adjustDate(inst, +7, 'D');
                        break; // +1 week on ctrl+down
            }
        else if (e.keyCode == 36 && e.ctrlKey) // display the date picker on ctrl+home
            $.datepicker._showDatepicker(this);
    },

    /* Filter entered characters - based on date format. */
    _doKeyPress: function(e) {
        var inst = $.datepicker._getInst(this._calId);
        var chars = $.datepicker._possibleChars(inst._get('dateFormat'));
        var chr = String.fromCharCode(e.charCode == undefined ? e.keyCode : e.charCode);
        return e.ctrlKey || (chr < ' ' || !chars || chars.indexOf(chr) > -1);
    },

    /* Attach the date picker to an input field. */
    _connectDatepicker: function(target, inst) {
        var input = $(target);
        if (input.is('.' + this.markerClassName))
            return;
        var appendText = inst._get('appendText');
        var isRTL = inst._get('isRTL');
        if (appendText) {
            if (isRTL)
                input.before('<span class="datepicker_append">' + appendText);
            else
                input.after('<span class="datepicker_append">' + appendText);
        }
        var showOn = inst._get('showOn');
        if (showOn == 'focus' || showOn == 'both') // pop-up date picker when in the marked field
            input.focus(this._showDatepicker);
        if (showOn == 'button' || showOn == 'both') { // pop-up date picker when button clicked
            input.wrap('<span class="datepicker_wrap">');
            var buttonText = inst._get('buttonText');
            var buttonImage = inst._get('buttonImage');
            var trigger = $(inst._get('buttonImageOnly') ? 
                $('<img>').addClass('datepicker_trigger').attr({ src: buttonImage, alt: buttonText, title: buttonText }) :
                $('<button>').addClass('datepicker_trigger').attr({ type: 'button' }).html(buttonImage != '' ? 
                        $('<img>').attr({ src:buttonImage, alt:buttonText, title:buttonText }) : buttonText));
            if (isRTL)
                input.before(trigger);
            else
                input.after(trigger);
            trigger.click(function() {
                if ($.datepicker._datepickerShowing && $.datepicker._lastInput == target)
                    $.datepicker._hideDatepicker();
                else
                    $.datepicker._showDatepicker(target);
            });
        }
        input.addClass(this.markerClassName).keydown(this._doKeyDown).keypress(this._doKeyPress)
            .bind("setData.datepicker", function(event, key, value) {
                inst._settings[key] = value;
            }).bind("getData.datepicker", function(event, key) {
                return inst._get(key);
            });
        input[0]._calId = inst._id;
    },

    /* Attach an inline date picker to a div. */
    _inlineDatepicker: function(target, inst) {
        var input = $(target);
        if (input.is('.' + this.markerClassName))
            return;
        input.addClass(this.markerClassName).append(inst._datepickerDiv)
            .bind("setData.datepicker", function(event, key, value){
                inst._settings[key] = value;
            }).bind("getData.datepicker", function(event, key){
                return inst._get(key);
            });
        input[0]._calId = inst._id;
        this._updateDatepicker(inst);
    },

    /* Tidy up after displaying the date picker. */
    _inlineShow: function(inst) {
        var numMonths = inst._getNumberOfMonths(); // fix width for dynamic number of date pickers
        inst._datepickerDiv.width(numMonths[1] * $('.datepicker', inst._datepickerDiv[0]).width());
    }, 

    /* Pop-up the date picker in a "dialog" box.
       @param  input     element - ignored
       @param  dateText  string - the initial date to display (in the current format)
       @param  onSelect  function - the function(dateText) to call when a date is selected
       @param  settings  object - update the dialog date picker instance's settings (anonymous object)
       @param  pos       int[2] - coordinates for the dialog's position within the screen or
                         event - with x/y coordinates or
                         leave empty for default (screen centre)
       @return the manager object */
    _dialogDatepicker: function(input, dateText, onSelect, settings, pos) {
        var inst = this._dialogInst; // internal instance
        if (!inst) {
            inst = this._dialogInst = new DatepickerInstance({}, false);
            this._dialogInput = $('<input type="text" size="1" style="position: absolute; top: -100px;"/>');
            this._dialogInput.keydown(this._doKeyDown);
            $('body').append(this._dialogInput);
            this._dialogInput[0]._calId = inst._id;
        }
        extendRemove(inst._settings, settings || {});
        this._dialogInput.val(dateText);

        this._pos = (pos ? (pos.length ? pos : [pos.pageX, pos.pageY]) : null);
        if (!this._pos) {
            var browserWidth = window.innerWidth || document.documentElement.clientWidth ||    document.body.clientWidth;
            var browserHeight = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
            var scrollX = document.documentElement.scrollLeft || document.body.scrollLeft;
            var scrollY = document.documentElement.scrollTop || document.body.scrollTop;
            this._pos = // should use actual width/height below
                [(browserWidth / 2) - 100 + scrollX, (browserHeight / 2) - 150 + scrollY];
        }

        // move input on screen for focus, but hidden behind dialog
        this._dialogInput.css('left', this._pos[0] + 'px').css('top', this._pos[1] + 'px');
        inst._settings.onSelect = onSelect;
        this._inDialog = true;
        this._datepickerDiv.addClass('datepicker_dialog');
        this._showDatepicker(this._dialogInput[0]);
        if ($.blockUI)
            $.blockUI(this._datepickerDiv);
        return this;
    },

    /* Pop-up the date picker for a given input field.
       @param  input  element - the input field attached to the date picker or
                      event - if triggered by focus */
    _showDatepicker: function(input) {
        input = input.target || input;
        if (input.nodeName.toLowerCase() != 'input') // find from button/image trigger
            input = $('input', input.parentNode)[0];
        if ($.datepicker._isDisabledDatepicker(input) || $.datepicker._lastInput == input) // already here
            return;
        var inst = $.datepicker._getInst(input._calId);
        var beforeShow = inst._get('beforeShow');
        extendRemove(inst._settings, (beforeShow ? beforeShow.apply(input, [input, inst]) : {}));
        $.datepicker._hideDatepicker(null, '');
        $.datepicker._lastInput = input;
        inst._setDateFromField(input);
        if ($.datepicker._inDialog) // hide cursor
            input.value = '';
        if (!$.datepicker._pos) { // position below input
            $.datepicker._pos = $.datepicker._findPos(input);
            $.datepicker._pos[1] += input.offsetHeight; // add the height
        }
        var isFixed = false;
        $(input).parents().each(function() {
            isFixed |= $(this).css('position') == 'fixed';
        });
        if (isFixed && $.browser.opera) { // correction for Opera when fixed and scrolled
            $.datepicker._pos[0] -= document.documentElement.scrollLeft;
            $.datepicker._pos[1] -= document.documentElement.scrollTop;
        }
        inst._datepickerDiv.css('position', ($.datepicker._inDialog && $.blockUI ?
            'static' : (isFixed ? 'fixed' : 'absolute')))
            .css({ left: $.datepicker._pos[0] + 'px', top: $.datepicker._pos[1] + 'px' });
        $.datepicker._pos = null;
        inst._rangeStart = null;
        $.datepicker._updateDatepicker(inst);
        if (!inst._inline) {
            var speed = inst._get('speed');
            var postProcess = function() {
                $.datepicker._datepickerShowing = true;
                $.datepicker._afterShow(inst);
            };
            var showAnim = inst._get('showAnim') || 'show';
            inst._datepickerDiv[showAnim](speed, postProcess);
            if (speed == '')
                postProcess();
            if (inst._input[0].type != 'hidden')
                inst._input[0].focus();
            $.datepicker._curInst = inst;
        }
    },

    /* Generate the date picker content. */
    _updateDatepicker: function(inst) {
        inst._datepickerDiv.empty().append(inst._generateDatepicker());
        var numMonths = inst._getNumberOfMonths();
        if (numMonths[0] != 1 || numMonths[1] != 1)
            inst._datepickerDiv.addClass('datepicker_multi');
        else
            inst._datepickerDiv.removeClass('datepicker_multi');

        if (inst._get('isRTL'))
            inst._datepickerDiv.addClass('datepicker_rtl');
        else
            inst._datepickerDiv.removeClass('datepicker_rtl');

        if (inst._input && inst._input[0].type != 'hidden')
            inst._input[0].focus();
    },

    /* Tidy up after displaying the date picker. */
    _afterShow: function(inst) {
        var numMonths = inst._getNumberOfMonths(); // fix width for dynamic number of date pickers
        inst._datepickerDiv.width(numMonths[1] * $('.datepicker', inst._datepickerDiv[0])[0].offsetWidth);
        if ($.browser.msie && parseInt($.browser.version) < 7) { // fix IE < 7 select problems
            $('#datepicker_cover').css({width: inst._datepickerDiv.width() + 4,
                height: inst._datepickerDiv.height() + 4});
        }
        // re-position on screen if necessary
        var isFixed = inst._datepickerDiv.css('position') == 'fixed';
        var pos = inst._input ? $.datepicker._findPos(inst._input[0]) : null;
        var browserWidth = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
        var browserHeight = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
        var scrollX = (isFixed ? 0 : document.documentElement.scrollLeft || document.body.scrollLeft);
        var scrollY = (isFixed ? 0 : document.documentElement.scrollTop || document.body.scrollTop);
        // reposition date picker horizontally if outside the browser window
        if ((inst._datepickerDiv.offset().left + inst._datepickerDiv.width() -
                (isFixed && $.browser.msie ? document.documentElement.scrollLeft : 0)) >
                (browserWidth + scrollX)) {
            inst._datepickerDiv.css('left', Math.max(scrollX,
                pos[0] + (inst._input ? $(inst._input[0]).width() : null) - inst._datepickerDiv.width() -
                (isFixed && $.browser.opera ? document.documentElement.scrollLeft : 0)) + 'px');
        }
        // reposition date picker vertically if outside the browser window
        if ((inst._datepickerDiv.offset().top + inst._datepickerDiv.height() -
                (isFixed && $.browser.msie ? document.documentElement.scrollTop : 0)) >
                (browserHeight + scrollY) ) {
            inst._datepickerDiv.css('top', Math.max(scrollY,
                pos[1] - (this._inDialog ? 0 : inst._datepickerDiv.height()) -
                (isFixed && $.browser.opera ? document.documentElement.scrollTop : 0)) + 'px');
        }
    },
    
    /* Find an object's position on the screen. */
    _findPos: function(obj) {
        while (obj && (obj.type == 'hidden' || obj.nodeType != 1)) {
            obj = obj.nextSibling;
        }
        var position = $(obj).offset();
        return [position.left, position.top];
    },

    /* Hide the date picker from view.
       @param  input  element - the input field attached to the date picker
       @param  speed  string - the speed at which to close the date picker */
    _hideDatepicker: function(input, speed) {
        var inst = this._curInst;
        if (!inst)
            return;
        var rangeSelect = inst._get('rangeSelect');
        if (rangeSelect && this._stayOpen) {
            this._selectDate(inst, inst._formatDate(
                inst._currentDay, inst._currentMonth, inst._currentYear));
        }
        this._stayOpen = false;
        if (this._datepickerShowing) {
            speed = (speed != null ? speed : inst._get('speed'));
            var showAnim = inst._get('showAnim');
            inst._datepickerDiv[(showAnim == 'slideDown' ? 'slideUp' :
                (showAnim == 'fadeIn' ? 'fadeOut' : 'hide'))](speed, function() {
                $.datepicker._tidyDialog(inst);
            });
            if (speed == '')
                this._tidyDialog(inst);
            var onClose = inst._get('onClose');
            if (onClose) {
                onClose.apply((inst._input ? inst._input[0] : null),
                    [inst._getDate(), inst]);  // trigger custom callback
            }
            this._datepickerShowing = false;
            this._lastInput = null;
            inst._settings.prompt = null;
            if (this._inDialog) {
                this._dialogInput.css({ position: 'absolute', left: '0', top: '-100px' });
                if ($.blockUI) {
                    $.unblockUI();
                    $('body').append(this._datepickerDiv);
                }
            }
            this._inDialog = false;
        }
        this._curInst = null;
    },

    /* Tidy up after a dialog display. */
    _tidyDialog: function(inst) {
        inst._datepickerDiv.removeClass('datepicker_dialog').unbind('.datepicker');
        $('.datepicker_prompt', inst._datepickerDiv).remove();
    },

    /* Close date picker if clicked elsewhere. */
    _checkExternalClick: function(event) {
        if (!$.datepicker._curInst)
            return;
        var $target = $(event.target);
        if (($target.parents("#datepicker_div").length == 0) &&
                ($target.attr('class') != 'datepicker_trigger') &&
                $.datepicker._datepickerShowing && !($.datepicker._inDialog && $.blockUI)) {
            $.datepicker._hideDatepicker(null, '');
        }
    },

    /* Adjust one of the date sub-fields. */
    _adjustDate: function(id, offset, period) {
        var inst = this._getInst(id);
        inst._adjustDate(offset, period);
        this._updateDatepicker(inst);
    },

    /* Action for current link. */
    _gotoToday: function(id) {
        var date = new Date();
        var inst = this._getInst(id);
        inst._selectedDay = date.getDate();
        inst._drawMonth = inst._selectedMonth = date.getMonth();
        inst._drawYear = inst._selectedYear = date.getFullYear();
        this._adjustDate(inst);
    },

    /* Action for selecting a new month/year. */
    _selectMonthYear: function(id, select, period) {
        var inst = this._getInst(id);
        inst._selectingMonthYear = false;
        inst[period == 'M' ? '_drawMonth' : '_drawYear'] =
            select.options[select.selectedIndex].value - 0;
        this._adjustDate(inst);
    },

    /* Restore input focus after not changing month/year. */
    _clickMonthYear: function(id) {
        var inst = this._getInst(id);
        if (inst._input && inst._selectingMonthYear && !$.browser.msie)
            inst._input[0].focus();
        inst._selectingMonthYear = !inst._selectingMonthYear;
    },

    /* Action for changing the first week day. */
    _changeFirstDay: function(id, day) {
        var inst = this._getInst(id);
        inst._settings.firstDay = day;
        this._updateDatepicker(inst);
    },

    /* Action for selecting a day. */
    _selectDay: function(id, month, year, td) {
        if ($(td).is('.datepicker_unselectable'))
            return;
        var inst = this._getInst(id);
        var rangeSelect = inst._get('rangeSelect');
        if (rangeSelect) {
            if (!this._stayOpen) {
                $('.datepicker td').removeClass('datepicker_currentDay');
                $(td).addClass('datepicker_currentDay');
            } 
            this._stayOpen = !this._stayOpen;
        }
        inst._selectedDay = inst._currentDay = $('a', td).html();
        inst._selectedMonth = inst._currentMonth = month;
        inst._selectedYear = inst._currentYear = year;
        this._selectDate(id, inst._formatDate(
            inst._currentDay, inst._currentMonth, inst._currentYear));
        if (this._stayOpen) {
            inst._endDay = inst._endMonth = inst._endYear = null;
            inst._rangeStart = new Date(inst._currentYear, inst._currentMonth, inst._currentDay);
            this._updateDatepicker(inst);
        }
        else if (rangeSelect) {
            inst._endDay = inst._currentDay;
            inst._endMonth = inst._currentMonth;
            inst._endYear = inst._currentYear;
            inst._selectedDay = inst._currentDay = inst._rangeStart.getDate();
            inst._selectedMonth = inst._currentMonth = inst._rangeStart.getMonth();
            inst._selectedYear = inst._currentYear = inst._rangeStart.getFullYear();
            inst._rangeStart = null;
            if (inst._inline)
                this._updateDatepicker(inst);
        }
    },

    /* Erase the input field and hide the date picker. */
    _clearDate: function(id) {
        var inst = this._getInst(id);
        if (inst._get('mandatory'))
            return;
        this._stayOpen = false;
        inst._endDay = inst._endMonth = inst._endYear = inst._rangeStart = null;
        this._selectDate(inst, '');
    },

    /* Update the input field with the selected date. */
    _selectDate: function(id, dateStr) {
        var inst = this._getInst(id);
        dateStr = (dateStr != null ? dateStr : inst._formatDate());
        if (inst._rangeStart)
            dateStr = inst._formatDate(inst._rangeStart) + inst._get('rangeSeparator') + dateStr;
        if (inst._input)
            inst._input.val(dateStr);
        var onSelect = inst._get('onSelect');
        if (onSelect)
            onSelect.apply((inst._input ? inst._input[0] : null), [dateStr, inst]);  // trigger custom callback
        else if (inst._input)
            inst._input.trigger('change'); // fire the change event
        if (inst._inline)
            this._updateDatepicker(inst);
        else if (!this._stayOpen) {
            this._hideDatepicker(null, inst._get('speed'));
            this._lastInput = inst._input[0];
            if (typeof(inst._input[0]) != 'object')
                inst._input[0].focus(); // restore focus
            this._lastInput = null;
        }
    },

    /* Set as beforeShowDay function to prevent selection of weekends.
       @param  date  Date - the date to customise
       @return [boolean, string] - is this date selectable?, what is its CSS class? */
    noWeekends: function(date) {
        var day = date.getDay();
        return [(day > 0 && day < 6), ''];
    },
    
    /* Set as calculateWeek to determine the week of the year based on the ISO 8601 definition.
       @param  date  Date - the date to get the week for
       @return  number - the number of the week within the year that contains this date */
    iso8601Week: function(date) {
        var checkDate = new Date(date.getFullYear(), date.getMonth(), date.getDate(), (date.getTimezoneOffset() / -60));
        var firstMon = new Date(checkDate.getFullYear(), 1 - 1, 4); // First week always contains 4 Jan
        var firstDay = firstMon.getDay() || 7; // Day of week: Mon = 1, ..., Sun = 7
        firstMon.setDate(firstMon.getDate() + 1 - firstDay); // Preceding Monday
        if (firstDay < 4 && checkDate < firstMon) { // Adjust first three days in year if necessary
            checkDate.setDate(checkDate.getDate() - 3); // Generate for previous year
            return $.datepicker.iso8601Week(checkDate);
        } else if (checkDate > new Date(checkDate.getFullYear(), 12 - 1, 28)) { // Check last three days in year
            firstDay = new Date(checkDate.getFullYear() + 1, 1 - 1, 4).getDay() || 7;
            if (firstDay > 4 && (checkDate.getDay() || 7) < firstDay - 3) { // Adjust if necessary
                checkDate.setDate(checkDate.getDate() + 3); // Generate for next year
                return $.datepicker.iso8601Week(checkDate);
            }
        }
        return Math.floor(((checkDate - firstMon) / 86400000) / 7) + 1; // Weeks to given date
    },
    
    /* Provide status text for a particular date.
       @param  date  the date to get the status for
       @param  inst  the current datepicker instance
       @return  the status display text for this date */
    dateStatus: function(date, inst) {
        return $.datepicker.formatDate(inst._get('dateStatus'), date, inst._getFormatConfig());
    },

    /* Parse a string value into a date object.
       The format can be combinations of the following:
       d  - day of month (no leading zero)
       dd - day of month (two digit)
       D  - day name short
       DD - day name long
       m  - month of year (no leading zero)
       mm - month of year (two digit)
       M  - month name short
       MM - month name long
       y  - year (two digit)
       yy - year (four digit)
       '...' - literal text
       '' - single quote

       @param  format           String - the expected format of the date
       @param  value            String - the date in the above format
       @param  settings  Object - attributes include:
                         shortYearCutoff  Number - the cutoff year for determining the century (optional)
                         dayNamesShort    String[7] - abbreviated names of the days from Sunday (optional)
                         dayNames         String[7] - names of the days from Sunday (optional)
                         monthNamesShort  String[12] - abbreviated names of the months (optional)
                         monthNames       String[12] - names of the months (optional)
       @return  Date - the extracted date value or null if value is blank */
    parseDate: function (format, value, settings) {
        if (format == null || value == null)
            throw 'Invalid arguments';
        value = (typeof value == 'object' ? value.toString() : value + '');
        if (value == '')
            return null;
        var shortYearCutoff = (settings ? settings.shortYearCutoff : null) || this._defaults.shortYearCutoff;
        var dayNamesShort = (settings ? settings.dayNamesShort : null) || this._defaults.dayNamesShort;
        var dayNames = (settings ? settings.dayNames : null) || this._defaults.dayNames;
        var monthNamesShort = (settings ? settings.monthNamesShort : null) || this._defaults.monthNamesShort;
        var monthNames = (settings ? settings.monthNames : null) || this._defaults.monthNames;
        var year = -1;
        var month = -1;
        var day = -1;
        var literal = false;
        // Check whether a format character is doubled
        var lookAhead = function(match) {
            var matches = (iFormat + 1 < format.length && format.charAt(iFormat + 1) == match);
            if (matches)
                iFormat++;
            return matches;    
        };
        // Extract a number from the string value
        var getNumber = function(match) {
            lookAhead(match);
            var size = (match == 'y' ? 4 : 2);
            var num = 0;
            while (size > 0 && iValue < value.length &&
                    value.charAt(iValue) >= '0' && value.charAt(iValue) <= '9') {
                num = num * 10 + (value.charAt(iValue++) - 0);
                size--;
            }
            if (size == (match == 'y' ? 4 : 2))
                throw 'Missing number at position ' + iValue;
            return num;
        };
        // Extract a name from the string value and convert to an index
        var getName = function(match, shortNames, longNames) {
            var names = (lookAhead(match) ? longNames : shortNames);
            var size = 0;
            for (var j = 0; j < names.length; j++)
                size = Math.max(size, names[j].length);
            var name = '';
            var iInit = iValue;
            while (size > 0 && iValue < value.length) {
                name += value.charAt(iValue++);
                for (var i = 0; i < names.length; i++)
                    if (name == names[i])
                        return i + 1;
                size--;
            }
            throw 'Unknown name at position ' + iInit;
        };
        // Confirm that a literal character matches the string value
        var checkLiteral = function() {
            if (value.charAt(iValue) != format.charAt(iFormat))
                throw 'Unexpected literal at position ' + iValue;
            iValue++;
        };
        var iValue = 0;
        for (var iFormat = 0; iFormat < format.length; iFormat++) {
            if (literal)
                if (format.charAt(iFormat) == "'" && !lookAhead("'"))
                    literal = false;
                else
                    checkLiteral();
            else
                switch (format.charAt(iFormat)) {
                    case 'd':
                        day = getNumber('d');
                        break;
                    case 'D': 
                        getName('D', dayNamesShort, dayNames);
                        break;
                    case 'm': 
                        month = getNumber('m');
                        break;
                    case 'M':
                        month = getName('M', monthNamesShort, monthNames); 
                        break;
                    case 'y':
                        year = getNumber('y');
                        break;
                    case "'":
                        if (lookAhead("'"))
                            checkLiteral();
                        else
                            literal = true;
                        break;
                    default:
                        checkLiteral();
                }
        }
        if (year < 100) {
            year += new Date().getFullYear() - new Date().getFullYear() % 100 +
                (year <= shortYearCutoff ? 0 : -100);
        }
        var date = new Date(year, month - 1, day);
        if (date.getFullYear() != year || date.getMonth() + 1 != month || date.getDate() != day) {
            throw 'Invalid date'; // E.g. 31/02/*
        }
        return date;
    },

    /* Format a date object into a string value.
       The format can be combinations of the following:
       d  - day of month (no leading zero)
       dd - day of month (two digit)
       D  - day name short
       DD - day name long
       m  - month of year (no leading zero)
       mm - month of year (two digit)
       M  - month name short
       MM - month name long
       y  - year (two digit)
       yy - year (four digit)
       '...' - literal text
       '' - single quote

       @param  format    String - the desired format of the date
       @param  date      Date - the date value to format
       @param  settings  Object - attributes include:
                         dayNamesShort    String[7] - abbreviated names of the days from Sunday (optional)
                         dayNames         String[7] - names of the days from Sunday (optional)
                         monthNamesShort  String[12] - abbreviated names of the months (optional)
                         monthNames       String[12] - names of the months (optional)
       @return  String - the date in the above format */
    formatDate: function (format, date, settings) {
        if (!date)
            return '';
        var dayNamesShort = (settings ? settings.dayNamesShort : null) || this._defaults.dayNamesShort;
        var dayNames = (settings ? settings.dayNames : null) || this._defaults.dayNames;
        var monthNamesShort = (settings ? settings.monthNamesShort : null) || this._defaults.monthNamesShort;
        var monthNames = (settings ? settings.monthNames : null) || this._defaults.monthNames;
        // Check whether a format character is doubled
        var lookAhead = function(match) {
            var matches = (iFormat + 1 < format.length && format.charAt(iFormat + 1) == match);
            if (matches)
                iFormat++;
            return matches;    
        };
        // Format a number, with leading zero if necessary
        var formatNumber = function(match, value) {
            return (lookAhead(match) && value < 10 ? '0' : '') + value;
        };
        // Format a name, short or long as requested
        var formatName = function(match, value, shortNames, longNames) {
            return (lookAhead(match) ? longNames[value] : shortNames[value]);
        };
        var output = '';
        var literal = false;
        if (date) {
            for (var iFormat = 0; iFormat < format.length; iFormat++) {
                if (literal)
                    if (format.charAt(iFormat) == "'" && !lookAhead("'"))
                        literal = false;
                    else
                        output += format.charAt(iFormat);
                else
                    switch (format.charAt(iFormat)) {
                        case 'd':
                            output += formatNumber('d', date.getDate()); 
                            break;
                        case 'D': 
                            output += formatName('D', date.getDay(), dayNamesShort, dayNames);
                            break;
                        case 'm': 
                            output += formatNumber('m', date.getMonth() + 1); 
                            break;
                        case 'M':
                            output += formatName('M', date.getMonth(), monthNamesShort, monthNames); 
                            break;
                        case 'y':
                            output += (lookAhead('y') ? date.getFullYear() : 
                                (date.getYear() % 100 < 10 ? '0' : '') + date.getYear() % 100);
                            break;
                        case "'":
                            if (lookAhead("'"))
                                output += "'";
                            else
                                literal = true;
                            break;
                        default:
                            output += format.charAt(iFormat);
                    }
            }
        }
        return output;
    },

    /* Extract all possible characters from the date format. */
    _possibleChars: function (format) {
        var chars = '';
        var literal = false;
        for (var iFormat = 0; iFormat < format.length; iFormat++)
            if (literal)
                if (format.charAt(iFormat) == "'" && !lookAhead("'"))
                    literal = false;
                else
                    chars += format.charAt(iFormat);
            else
                switch (format.charAt(iFormat)) {
                    case 'd' || 'm' || 'y':
                        chars += '0123456789'; 
                        break;
                    case 'D' || 'M':
                        return null; // Accept anything
                    case "'":
                        if (lookAhead("'"))
                            chars += "'";
                        else
                            literal = true;
                        break;
                    default:
                        chars += format.charAt(iFormat);
                }
        return chars;
    }
});

/* Individualised settings for date picker functionality applied to one or more related inputs.
   Instances are managed and manipulated through the Datepicker manager. */
function DatepickerInstance(settings, inline) {
    this._id = $.datepicker._register(this);
    this._selectedDay = 0; // Current date for selection
    this._selectedMonth = 0; // 0-11
    this._selectedYear = 0; // 4-digit year
    this._drawMonth = 0; // Current month at start of datepicker
    this._drawYear = 0;
    this._input = null; // The attached input field
    this._inline = inline; // True if showing inline, false if used in a popup
    this._datepickerDiv = (!inline ? $.datepicker._datepickerDiv :
        $('<div id="datepicker_div_' + this._id + '" class="datepicker_inline">'));
    // customise the date picker object - uses manager defaults if not overridden
    this._settings = extendRemove(settings || {}); // clone
    if (inline)
        this._setDate(this._getDefaultDate());
}

$.extend(DatepickerInstance.prototype, {
    /* Get a setting value, defaulting if necessary. */
    _get: function(name) {
        return this._settings[name] || $.datepicker._defaults[name];
    },

    /* Parse existing date and initialise date picker. */
    _setDateFromField: function(input) {
        this._input = $(input);
        var dateFormat = this._get('dateFormat');
        var dates = this._input ? this._input.val().split(this._get('rangeSeparator')) : null; 
        this._endDay = this._endMonth = this._endYear = null;
        var date = defaultDate = this._getDefaultDate();
        if (dates.length > 0) {
            var settings = this._getFormatConfig();
            if (dates.length > 1) {
                date = $.datepicker.parseDate(dateFormat, dates[1], settings) || defaultDate;
                this._endDay = date.getDate();
                this._endMonth = date.getMonth();
                this._endYear = date.getFullYear();
            }
            try {
                date = $.datepicker.parseDate(dateFormat, dates[0], settings) || defaultDate;
            } catch (e) {
                $.datepicker.log(e);
                date = defaultDate;
            }
        }
        this._selectedDay = date.getDate();
        this._drawMonth = this._selectedMonth = date.getMonth();
        this._drawYear = this._selectedYear = date.getFullYear();
        this._currentDay = (dates[0] ? date.getDate() : 0);
        this._currentMonth = (dates[0] ? date.getMonth() : 0);
        this._currentYear = (dates[0] ? date.getFullYear() : 0);
        this._adjustDate();
    },
    
    /* Retrieve the default date shown on opening. */
    _getDefaultDate: function() {
        var date = this._determineDate('defaultDate', new Date());
        var minDate = this._getMinMaxDate('min', true);
        var maxDate = this._getMinMaxDate('max');
        date = (minDate && date < minDate ? minDate : date);
        date = (maxDate && date > maxDate ? maxDate : date);
        return date;
    },

    /* A date may be specified as an exact value or a relative one. */
    _determineDate: function(name, defaultDate) {
        var offsetNumeric = function(offset) {
            var date = new Date();
            date.setDate(date.getDate() + offset);
            return date;
        };
        var offsetString = function(offset, getDaysInMonth) {
            var date = new Date();
            var matches = /^([+-]?[0-9]+)\s*(d|D|w|W|m|M|y|Y)?$/.exec(offset);
            if (matches) {
                var year = date.getFullYear();
                var month = date.getMonth();
                var day = date.getDate();
                switch (matches[2] || 'd') {
                    case 'd' : case 'D' :
                        day += (matches[1] - 0); break;
                    case 'w' : case 'W' :
                        day += (matches[1] * 7); break;
                    case 'm' : case 'M' :
                        month += (matches[1] - 0); 
                        day = Math.min(day, getDaysInMonth(year, month));
                        break;
                    case 'y': case 'Y' :
                        year += (matches[1] - 0);
                        day = Math.min(day, getDaysInMonth(year, month));
                        break;
                }
                date = new Date(year, month, day);
            }
            return date;
        };
        var date = this._get(name);
        return (date == null ? defaultDate :
            (typeof date == 'string' ? offsetString(date, this._getDaysInMonth) :
            (typeof date == 'number' ? offsetNumeric(date) : date)));
    },

    /* Set the date(s) directly. */
    _setDate: function(date, endDate) {
        this._selectedDay = this._currentDay = date.getDate();
        this._drawMonth = this._selectedMonth = this._currentMonth = date.getMonth();
        this._drawYear = this._selectedYear = this._currentYear = date.getFullYear();
        if (this._get('rangeSelect')) {
            if (endDate) {
                this._endDay = endDate.getDate();
                this._endMonth = endDate.getMonth();
                this._endYear = endDate.getFullYear();
            } else {
                this._endDay = this._currentDay;
                this._endMonth = this._currentMonth;
                this._endYear = this._currentYear;
            }
        }
        this._adjustDate();
    },

    /* Retrieve the date(s) directly. */
    _getDate: function() {
        var startDate = (!this._currentYear || (this._input && this._input.val() == '') ? null :
            new Date(this._currentYear, this._currentMonth, this._currentDay));
        if (this._get('rangeSelect')) {
            return [startDate, (!this._endYear ? null :
                new Date(this._endYear, this._endMonth, this._endDay))];
        } else
            return startDate;
    },

    /* Generate the HTML for the current state of the date picker. */
    _generateDatepicker: function() {
        var today = new Date();
        today = new Date(today.getFullYear(), today.getMonth(), today.getDate()); // clear time
        var showStatus = this._get('showStatus');
        var isRTL = this._get('isRTL');
        // build the date picker HTML
        var clear = (this._get('mandatory') ? '' :
            '<div class="datepicker_clear"><a onclick="jQuery.datepicker._clearDate(' + this._id + ');"' + 
            (showStatus ? this._addStatus(this._get('clearStatus') || '&#xa0;') : '') + '>' +
            this._get('clearText') + '</a></div>');
        var controls = '<div class="datepicker_control">' + (isRTL ? '' : clear) +
            '<div class="datepicker_close"><a onclick="jQuery.datepicker._hideDatepicker();"' +
            (showStatus ? this._addStatus(this._get('closeStatus') || '&#xa0;') : '') + '>' +
            this._get('closeText') + '</a></div>' + (isRTL ? clear : '')  + '</div>';
        var prompt = this._get('prompt');
        var closeAtTop = this._get('closeAtTop');
        var hideIfNoPrevNext = this._get('hideIfNoPrevNext');
        var numMonths = this._getNumberOfMonths();
        var stepMonths = this._get('stepMonths');
        var isMultiMonth = (numMonths[0] != 1 || numMonths[1] != 1);
        var minDate = this._getMinMaxDate('min', true);
        var maxDate = this._getMinMaxDate('max');
        var drawMonth = this._drawMonth;
        var drawYear = this._drawYear;
        if (maxDate) {
            var maxDraw = new Date(maxDate.getFullYear(),
                maxDate.getMonth() - numMonths[1] + 1, maxDate.getDate());
            maxDraw = (minDate && maxDraw < minDate ? minDate : maxDraw);
            while (new Date(drawYear, drawMonth, 1) > maxDraw) {
                drawMonth--;
                if (drawMonth < 0) {
                    drawMonth = 11;
                    drawYear--;
                }
            }
        }
        // controls and links
        var prev = '<div class="datepicker_prev">' + (this._canAdjustMonth(-1, drawYear, drawMonth) ? 
            '<a onclick="jQuery.datepicker._adjustDate(' + this._id + ', -' + stepMonths + ', \'M\');"' +
            (showStatus ? this._addStatus(this._get('prevStatus') || '&#xa0;') : '') + '>' +
            this._get('prevText') + '</a>' :
            (hideIfNoPrevNext ? '' : '<label>' + this._get('prevText') + '</label>')) + '</div>';
        var next = '<div class="datepicker_next">' + (this._canAdjustMonth(+1, drawYear, drawMonth) ?
            '<a onclick="jQuery.datepicker._adjustDate(' + this._id + ', +' + stepMonths + ', \'M\');"' +
            (showStatus ? this._addStatus(this._get('nextStatus') || '&#xa0;') : '') + '>' +
            this._get('nextText') + '</a>' :
            (hideIfNoPrevNext ? '>' : '<label>' + this._get('nextText') + '</label>')) + '</div>';
        var html = (prompt ? '<div class="datepicker_prompt">' + prompt + '</div>' : '') +
            (closeAtTop && !this._inline ? controls : '') +
            '<div class="datepicker_links">' + (isRTL ? next : prev) +
            (this._isInRange(today) ? '<div class="datepicker_current">' +
            '<a onclick="jQuery.datepicker._gotoToday(' + this._id + ');"' +
            (showStatus ? this._addStatus(this._get('currentStatus') || '&#xa0;') : '') + '>' +
            this._get('currentText') + '</a></div>' : '') + (isRTL ? prev : next) + '</div>';
        var showWeeks = this._get('showWeeks');
        for (var row = 0; row < numMonths[0]; row++)
            for (var col = 0; col < numMonths[1]; col++) {
                var selectedDate = new Date(drawYear, drawMonth, this._selectedDay);
                html += '<div class="datepicker_oneMonth' + (col == 0 ? ' datepicker_newRow' : '') + '">' +
                    this._generateMonthYearHeader(drawMonth, drawYear, minDate, maxDate,
                    selectedDate, row > 0 || col > 0) + // draw month headers
                    '<table class="datepicker" cellpadding="0" cellspacing="0"><thead>' + 
                    '<tr class="datepicker_titleRow">' +
                    (showWeeks ? '<td>' + this._get('weekHeader') + '</td>' : '');
                var firstDay = this._get('firstDay');
                var changeFirstDay = this._get('changeFirstDay');
                var dayNames = this._get('dayNames');
                var dayNamesShort = this._get('dayNamesShort');
                var dayNamesMin = this._get('dayNamesMin');
                for (var dow = 0; dow < 7; dow++) { // days of the week
                    var day = (dow + firstDay) % 7;
                    var status = this._get('dayStatus') || '&#xa0;';
                    status = (status.indexOf('DD') > -1 ? status.replace(/DD/, dayNames[day]) :
                        status.replace(/D/, dayNamesShort[day]));
                    html += '<td' + ((dow + firstDay + 6) % 7 >= 5 ? ' class="datepicker_weekEndCell"' : '') + '>' +
                        (!changeFirstDay ? '<span' :
                        '<a onclick="jQuery.datepicker._changeFirstDay(' + this._id + ', ' + day + ');"') + 
                        (showStatus ? this._addStatus(status) : '') + ' title="' + dayNames[day] + '">' +
                        dayNamesMin[day] + (changeFirstDay ? '</a>' : '</span>') + '</td>';
                }
                html += '</tr></thead><tbody>';
                var daysInMonth = this._getDaysInMonth(drawYear, drawMonth);
                if (drawYear == this._selectedYear && drawMonth == this._selectedMonth) {
                    this._selectedDay = Math.min(this._selectedDay, daysInMonth);
                }
                var leadDays = (this._getFirstDayOfMonth(drawYear, drawMonth) - firstDay + 7) % 7;
                var currentDate = (!this._currentDay ? new Date(9999, 9, 9) :
                    new Date(this._currentYear, this._currentMonth, this._currentDay));
                var endDate = this._endDay ? new Date(this._endYear, this._endMonth, this._endDay) : currentDate;
                var printDate = new Date(drawYear, drawMonth, 1 - leadDays);
                var numRows = (isMultiMonth ? 6 : Math.ceil((leadDays + daysInMonth) / 7)); // calculate the number of rows to generate
                var beforeShowDay = this._get('beforeShowDay');
                var showOtherMonths = this._get('showOtherMonths');
                var calculateWeek = this._get('calculateWeek') || $.datepicker.iso8601Week;
                var dateStatus = this._get('statusForDate') || $.datepicker.dateStatus;
                for (var dRow = 0; dRow < numRows; dRow++) { // create date picker rows
                    html += '<tr class="datepicker_daysRow">' +
                        (showWeeks ? '<td class="datepicker_weekCol">' + calculateWeek(printDate) + '</td>' : '');
                    for (var dow = 0; dow < 7; dow++) { // create date picker days
                        var daySettings = (beforeShowDay ?
                            beforeShowDay.apply((this._input ? this._input[0] : null), [printDate]) : [true, '']);
                        var otherMonth = (printDate.getMonth() != drawMonth);
                        var unselectable = otherMonth || !daySettings[0] ||
                            (minDate && printDate < minDate) || (maxDate && printDate > maxDate);
                        html += '<td class="datepicker_daysCell' +
                            ((dow + firstDay + 6) % 7 >= 5 ? ' datepicker_weekEndCell' : '') + // highlight weekends
                            (otherMonth ? ' datepicker_otherMonth' : '') + // highlight days from other months
                            (printDate.getTime() == selectedDate.getTime() && drawMonth == this._selectedMonth ?
                            ' datepicker_daysCellOver' : '') + // highlight selected day
                            (unselectable ? ' datepicker_unselectable' : '') +  // highlight unselectable days
                            (otherMonth && !showOtherMonths ? '' : ' ' + daySettings[1] + // highlight custom dates
                            (printDate.getTime() >= currentDate.getTime() && printDate.getTime() <= endDate.getTime() ?  // in current range
                            ' datepicker_currentDay' : '') + // highlight selected day
                            (printDate.getTime() == today.getTime() ? ' datepicker_today' : '')) + '"' + // highlight today (if different)
                            (unselectable ? '' : ' onmouseover="jQuery(this).addClass(\'datepicker_daysCellOver\');' +
                            (!showStatus || (otherMonth && !showOtherMonths) ? '' : 'jQuery(\'#datepicker_status_' +
                            this._id + '\').html(\'' + (dateStatus.apply((this._input ? this._input[0] : null),
                            [printDate, this]) || '&#xa0;') +'\');') + '"' +
                            ' onmouseout="jQuery(this).removeClass(\'datepicker_daysCellOver\');' +
                            (!showStatus || (otherMonth && !showOtherMonths) ? '' : 'jQuery(\'#datepicker_status_' +
                            this._id + '\').html(\'&#xa0;\');') + '" onclick="jQuery.datepicker._selectDay(' +
                            this._id + ',' + drawMonth + ',' + drawYear + ', this);"') + '>' + // actions
                            (otherMonth ? (showOtherMonths ? printDate.getDate() : '&#xa0;') : // display for other months
                            (unselectable ? printDate.getDate() : '<a>' + printDate.getDate() + '</a>')) + '</td>'; // display for this month
                        printDate.setDate(printDate.getDate() + 1);
                    }
                    html += '</tr>';
                }
                drawMonth++;
                if (drawMonth > 11) {
                    drawMonth = 0;
                    drawYear++;
                }
                html += '</tbody></table></div>';
            }
        html += (showStatus ? '<div id="datepicker_status_' + this._id + 
            '" class="datepicker_status">' + (this._get('initStatus') || '&#xa0;') + '</div>' : '') +
            (!closeAtTop && !this._inline ? controls : '') +
            '<div style="clear: both;"></div>' + 
            ($.browser.msie && parseInt($.browser.version) < 7 && !this._inline ? 
            '<iframe src="javascript:false;" class="datepicker_cover"></iframe>' : '');
        return html;
    },
    
    /* Generate the month and year header. */
    _generateMonthYearHeader: function(drawMonth, drawYear, minDate, maxDate, selectedDate, secondary) {
        minDate = (this._rangeStart && minDate && selectedDate < minDate ? selectedDate : minDate);
        var showStatus = this._get('showStatus');
        var html = '<div class="datepicker_header">';
        // month selection
        var monthNames = this._get('monthNames');
        if (secondary || !this._get('changeMonth'))
            html += monthNames[drawMonth] + '&#xa0;';
            
        else {
            var inMinYear = (minDate && minDate.getFullYear() == drawYear);
            var inMaxYear = (maxDate && maxDate.getFullYear() == drawYear);
            html += '<select class="datepicker_newMonth" ' +
                'onchange="jQuery.datepicker._selectMonthYear(' + this._id + ', this, \'M\');" ' +
                'onclick="jQuery.datepicker._clickMonthYear(' + this._id + ');"' +
                (showStatus ? this._addStatus(this._get('monthStatus') || '&#xa0;') : '') + '>';
            for (var month = 0; month < 12; month++) {
                if ((!inMinYear || month >= minDate.getMonth()) &&
                        (!inMaxYear || month <= maxDate.getMonth())) {
                    html += '<option value="' + month + '"' +
                        (month == drawMonth ? ' selected="selected"' : '') +
                        '>' + monthNames[month] + '</option>';
                }
            }
            html += '</select>';
        }
        // year selection
        if (secondary || !this._get('changeYear'))
            html += drawYear;
        else {
            // determine range of years to display
            var years = this._get('yearRange').split(':');
            var year = 0;
            var endYear = 0;
            if (years.length != 2) {
                year = drawYear - 10;
                endYear = drawYear + 10;
            } else if (years[0].charAt(0) == '+' || years[0].charAt(0) == '-') {
                year = drawYear + parseInt(years[0], 10);
                endYear = drawYear + parseInt(years[1], 10);
            } else {
                year = parseInt(years[0], 10);
                endYear = parseInt(years[1], 10);
            }
            year = (minDate ? Math.max(year, minDate.getFullYear()) : year);
            endYear = (maxDate ? Math.min(endYear, maxDate.getFullYear()) : endYear);
            html += '<select class="datepicker_newYear" ' +
                'onchange="jQuery.datepicker._selectMonthYear(' + this._id + ', this, \'Y\');" ' +
                'onclick="jQuery.datepicker._clickMonthYear(' + this._id + ');"' +
                (showStatus ? this._addStatus(this._get('yearStatus') || '&#xa0;') : '') + '>';
            for (; year <= endYear; year++) {
                html += '<option value="' + year + '"' +
                    (year == drawYear ? ' selected="selected"' : '') +
                    '>' + year + '</option>';
            }
            html += '</select>';
        }
        html += '</div>'; // Close datepicker_header
        return html;
    },

    /* Provide code to set and clear the status panel. */
    _addStatus: function(text) {
        return ' onmouseover="jQuery(\'#datepicker_status_' + this._id + '\').html(\'' + text + '\');" ' +
            'onmouseout="jQuery(\'#datepicker_status_' + this._id + '\').html(\'&#xa0;\');"';
    },

    /* Adjust one of the date sub-fields. */
    _adjustDate: function(offset, period) {
        var year = this._drawYear + (period == 'Y' ? offset : 0);
        var month = this._drawMonth + (period == 'M' ? offset : 0);
        var day = Math.min(this._selectedDay, this._getDaysInMonth(year, month)) +
            (period == 'D' ? offset : 0);
        var date = new Date(year, month, day);
        // ensure it is within the bounds set
        var minDate = this._getMinMaxDate('min', true);
        var maxDate = this._getMinMaxDate('max');
        date = (minDate && date < minDate ? minDate : date);
        date = (maxDate && date > maxDate ? maxDate : date);
        this._selectedDay = date.getDate();
        this._drawMonth = this._selectedMonth = date.getMonth();
        this._drawYear = this._selectedYear = date.getFullYear();
    },
    
    /* Determine the number of months to show. */
    _getNumberOfMonths: function() {
        var numMonths = this._get('numberOfMonths');
        return (numMonths == null ? [1, 1] : (typeof numMonths == 'number' ? [1, numMonths] : numMonths));
    },

    /* Determine the current maximum date - ensure no time components are set - may be overridden for a range. */
    _getMinMaxDate: function(minMax, checkRange) {
        var date = this._determineDate(minMax + 'Date', null);
        if (date) {
            date.setHours(0);
            date.setMinutes(0);
            date.setSeconds(0);
            date.setMilliseconds(0);
        }
        return date || (checkRange ? this._rangeStart : null);
    },

    /* Find the number of days in a given month. */
    _getDaysInMonth: function(year, month) {
        return 32 - new Date(year, month, 32).getDate();
    },

    /* Find the day of the week of the first of a month. */
    _getFirstDayOfMonth: function(year, month) {
        return new Date(year, month, 1).getDay();
    },

    /* Determines if we should allow a "next/prev" month display change. */
    _canAdjustMonth: function(offset, curYear, curMonth) {
        var numMonths = this._getNumberOfMonths();
        var date = new Date(curYear, curMonth + (offset < 0 ? offset : numMonths[1]), 1);
        if (offset < 0)
            date.setDate(this._getDaysInMonth(date.getFullYear(), date.getMonth()));
        return this._isInRange(date);
    },

    /* Is the given date in the accepted range? */
    _isInRange: function(date) {
        // during range selection, use minimum of selected date and range start
        var newMinDate = (!this._rangeStart ? null :
            new Date(this._selectedYear, this._selectedMonth, this._selectedDay));
        newMinDate = (newMinDate && this._rangeStart < newMinDate ? this._rangeStart : newMinDate);
        var minDate = newMinDate || this._getMinMaxDate('min');
        var maxDate = this._getMinMaxDate('max');
        return ((!minDate || date >= minDate) && (!maxDate || date <= maxDate));
    },
    
    /* Provide the configuration settings for formatting/parsing. */
    _getFormatConfig: function() {
        var shortYearCutoff = this._get('shortYearCutoff');
        shortYearCutoff = (typeof shortYearCutoff != 'string' ? shortYearCutoff :
            new Date().getFullYear() % 100 + parseInt(shortYearCutoff, 10));
        return {shortYearCutoff: shortYearCutoff,
            dayNamesShort: this._get('dayNamesShort'), dayNames: this._get('dayNames'),
            monthNamesShort: this._get('monthNamesShort'), monthNames: this._get('monthNames')};
    },

    /* Format the given date for display. */
    _formatDate: function(day, month, year) {
        if (!day) {
            this._currentDay = this._selectedDay;
            this._currentMonth = this._selectedMonth;
            this._currentYear = this._selectedYear;
        }
        var date = (day ? (typeof day == 'object' ? day : new Date(year, month, day)) :
            new Date(this._currentYear, this._currentMonth, this._currentDay));
        return $.datepicker.formatDate(this._get('dateFormat'), date, this._getFormatConfig());
    }
});

/* jQuery extend now ignores nulls! */
function extendRemove(target, props) {
    $.extend(target, props);
    for (var name in props)
        if (props[name] == null)
            target[name] = null;
    return target;
};

/* Invoke the datepicker functionality.
   @param  options  String - a command, optionally followed by additional parameters or
                    Object - settings for attaching new datepicker functionality
   @return  jQuery object */
$.fn.datepicker = function(options){
    var otherArgs = Array.prototype.slice.call(arguments, 1);
    if (typeof options == 'string' && (options == 'isDisabled' || options == 'getDate')) {
        return $.datepicker['_' + options + 'Datepicker'].apply($.datepicker, [this[0]].concat(otherArgs));
    }
    return this.each(function() {
        typeof options == 'string' ?
            $.datepicker['_' + options + 'Datepicker'].apply($.datepicker, [this].concat(otherArgs)) :
            $.datepicker._attachDatepicker(this, options);
    });
};
    
/* Initialise the date picker. */
$(document).ready(function() {
    $(document.body).append($.datepicker._datepickerDiv)
        .mousedown($.datepicker._checkExternalClick);
});

$.datepicker = new Datepicker(); // singleton instance

})(jQuery);