// Calendar: a Javascript class for Mootools that adds accessible and unobtrusive date pickers to your form elements <http://electricprism.com/aeron/calendar>
// Calendar RC4, Copyright (c) 2007 Aeron Glemann <http://electricprism.com/aeron>, MIT Style License.
// Mootools 1.2 compatibility by Davorin Šego

/*
Quelle: http://www.electricprism.com/aeron/calendar/
File: calendar.compat.js

Safog.com Anpassungen
	options: lang hinzugefügt
	wenn lang ein string ist werden die sprachbed. 
	Tage und Monate innerhalb der Klasse beforzugt, ansonsten müssen sie übergeben werden (days, months).
	Ebenfalls wird das Datumsformat sprachbed. in der Klasse festgelegt 
	(andernfalls das Format beim objekt beim aufruf der klasse angeben).
	options: strRelScrollID hinzugefügt
	ElementID innerhalb des windows angeben, von dem die Scroll-Werte ermittelt werden sollen. Wenn leer bezug = window.
*/

var Calendar = new Class({	

  Implements: Options,

	options: {
		lang: false, // Safog.com: false oder string
		blocked: [], // blocked dates z.B. '20-25,31 12 *'
		classes: [], // ['calendar', 'prev', 'next', 'month', 'year', 'today', 'invalid', 'valid', 'inactive', 'active', 'hover', 'hilite']
		days: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'], // days of the week starting at sunday
		direction: 1, // -1 past, 0 past + future, 1 future
		draggable: false,
		months: ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],
		navigation: 1, // 0 = no nav; 1 = single nav for month; 2 = dual nav for month and year
		offset: 0, // first day of the week: 0 = sunday, 1 = monday, etc..
		strRelScrollID: '', // Safog.com: eingeführt -> Element innerhalb des windows angeben, von dem die Scroll-Werte ermittelt werden sollen. Wenn leer bezug = window
		onHideStart: Class.empty,
		onHideComplete: Class.empty,
		onShowStart: Class.empty,
		onShowComplete: Class.empty,
		pad: 1, // padding between multiple calendars
		tweak: {x: 5, y: 0} // tweak calendar positioning
	},

	// initialize: calendar constructor
	// @param obj (obj) a js object containing the form elements and format strings { id: 'format', id: 'format' etc }
	// @param props (obj) optional properties

	initialize: function(obj, options) {
		// basic error checking
		if (!obj) { return false; }
		this.setOptions(options);
		
		// Safog.com
		// Sprachbedingte options hierher verlager BOF
		if( this.options.lang ){
			switch( this.options.lang ){
			case 'it':
				this.options.days = [ 'Domenica', 'Lunedì', 'Martedì', 'Mercoledì', 'Giovedì', 'Venerdì', 'Sabato' ];
				this.options.months = ['Gennaio', 'Febbraio', 'Marzo', 'Aprile', 'Maggio', 'Giugno', 'Luglio', 'Agosto', 'Settembre', 'Ottobre', 'Novembre', 'Dicembre' ];
				this.m_strDateFormat = 'd/m/Y';
				break;
			case 'en':
				this.options.days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
				this.options.months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
				this.m_strDateFormat = 'm-d-Y';
				break;
			default:
				this.options.days = [ 'Sonntag', 'Montag', 'Dienstag', 'Mittwoch', 'Donnerstag', 'Freitag', 'Samstag' ];
				this.options.months = ['Januar', 'Februar', 'März', 'April', 'Mai', 'Juni', 'Juli', 'August', 'September', 'Oktober', 'November', 'Dezember' ];
				this.m_strDateFormat = 'd.m.Y';
				break;
			}
		}
		// Sprachbedingte options hierher verlager EOF
		
		

		// create our classes array
		var keys = ['calendar', 'prev', 'next', 'month', 'year', 'today', 'invalid', 'valid', 'inactive', 'active', 'hover', 'hilite'];

		var values = keys.map(function(key, i) {
			if (this.options.classes[i]) {
				if (this.options.classes[i].length) { key = this.options.classes[i]; }
			}
			return key;
		}, this);

		this.classes = values.associate(keys);

		// create cal element with css styles required for proper cal functioning
		this.calendar = new Element('div', { 
			'styles': { left: '-1000px', opacity: 0, position: 'absolute', top: '-1000px', zIndex: 1000 }
		}).addClass(this.classes.calendar).injectInside(document.body);

		// iex 6 needs a transparent iframe underneath the calendar in order to not allow select elements to render through
		if (window.ie6) {
			this.iframe = new Element('iframe', { 
				'styles': { left: '-1000px', position: 'absolute', top: '-1000px', zIndex: 999 }
			}).injectInside(document.body);
			this.iframe.style.filter = 'progid:DXImageTransform.Microsoft.Alpha(style=0,opacity=0)';
		}

		// initialize fade method
		this.fx = new Fx.Tween(this.calendar, {
			onStart: function() { 
				if (this.calendar.getStyle('opacity') == 0) { // show
					if (window.ie6) { this.iframe.setStyle('display', 'block'); }
					this.calendar.setStyle('display', 'block');
					this.fireEvent('onShowStart', this.element);
				}
				else { // hide
					this.fireEvent('onHideStart', this.element);
				}
			}.bind(this),
			onComplete: function() { 
				if (this.calendar.getStyle('opacity') == 0) { // hidden
					this.calendar.setStyle('display', 'none');
					if (window.ie6) { this.iframe.setStyle('display', 'none'); }
					this.fireEvent('onHideComplete', this.element);
				}
				else { // shown
					this.fireEvent('onShowComplete', this.element);
				}
			}.bind(this)
		});

		// initialize drag method
		if (window.Drag && this.options.draggable) {
			this.drag = new Drag.Move(this.calendar, { 
				onDrag: function() {
					if (window.ie6) { this.iframe.setStyles({ left: this.calendar.style.left, top: this.calendar.style.top }); } 
				}.bind(this) 
			}); 
		}
		
		// create calendars array
		this.calendars = [];

		var id = 0;
		var d = new Date(); // today

		d.setDate(d.getDate() + this.options.direction.toInt()); // correct today for directional offset

		for (var i in obj) {
			var cal = { 
				button: new Element('button', { 'type': 'button' }),
				el: $(i),
				els: [],
				id: id++,
				month: d.getMonth(),
				visible: false,
				year: d.getFullYear()
			};

			// fix for bad element (naughty, naughty element!)
			if (!this.element(i, obj[i], cal)) { continue; }
			
			cal.el.addClass(this.classes.calendar);

			// create cal button
			cal.button.addClass(this.classes.calendar).addEvent('click', function(cal) { this.toggle(cal); }.pass(cal, this)).injectAfter(cal.el);

			// read in default value
			cal.val = this.read(cal);
			
			$extend(cal, this.bounds(cal)); // abs bounds of calendar

			$extend(cal, this.values(cal)); // valid days, months, years

			this.rebuild(cal);

			this.calendars.push(cal); // add to cals array		
		}	
	},


	// blocked: returns an array of blocked days for the month / year
	// @param cal (obj)
	// @returns blocked days (array)

	blocked: function(cal) {
		var blocked = [];
		var offset = new Date(cal.year, cal.month, 1).getDay(); // day of the week (offset)
		var last = new Date(cal.year, cal.month + 1, 0).getDate(); // last day of this month
		
		this.options.blocked.each(function(date){
			var values = date.split(' ');
			
			// preparation
			for (var i = 0; i <= 3; i++){ 
				if (!values[i]){ values[i] = (i == 3) ? '' : '*'; } // make sure blocked date contains values for at least d, m and y
				values[i] = values[i].contains(',') ? values[i].split(',') : new Array(values[i]); // split multiple values
				var count = values[i].length - 1;
				for (var j = count; j >= 0; j--){
					if (values[i][j].contains('-')){ // a range
						var val = values[i][j].split('-');
						for (var k = val[0]; k <= val[1]; k++){
							if (!values[i].contains(k)){ values[i].push(k + ''); }
						}
						values[i].splice(j, 1);
					}
				}
			}

			// execution
			if (values[2].contains(cal.year + '') || values[2].contains('*')){
				if (values[1].contains(cal.month + 1 + '') || values[1].contains('*')){
					values[0].each(function(val){ // if blocked value indicates this month / year
						if (val > 0){ blocked.push(val.toInt()); } // add date to blocked array
					});

					if (values[3]){ // optional value for day of week
						for (var i = 0; i < last; i++){
								var day = (i + offset) % 7;
	
								if (values[3].contains(day + '')){ 
									blocked.push(i + 1); // add every date that corresponds to the blocked day of the week to the blocked array
								}
						}
					}
				}
			}
		}, this);

		return blocked;
	},


	// bounds: returns the start / end bounds of the calendar
	// @param cal (obj)
	// @returns obj	

	bounds: function(cal) {
		// 1. first we assume the calendar has no bounds (or a thousand years in either direction)
		
		// by default the calendar will accept a millennium in either direction
		var start = new Date(1000, 0, 1); // jan 1, 1000
		var end = new Date(2999, 11, 31); // dec 31, 2999

		// 2. but if the cal is one directional we adjust accordingly
		var date = new Date().getDate() + this.options.direction.toInt();

		if (this.options.direction > 0) {
			start = new Date();
			start.setDate(date + this.options.pad * cal.id);
		}
		
		if (this.options.direction < 0) {
			end = new Date();
			end.setDate(date - this.options.pad * (this.calendars.length - cal.id - 1));
		}

		// 3. then we can further filter the limits by using the pre-existing values in the selects
		cal.els.each(function(el) {	
			if (el.get('tag') == 'select') {		
				if (el.format.test('(y|Y)')) { // search for a year select
					var years = [];

					el.getChildren().each(function(option) { // get options
						var values = this.unformat(option.value, el.format);
	
						if (!years.contains(values[0])) { years.push(values[0]); } // add to years array
					}, this);
	
					years.sort(this.sort);
			
					if (years[0] > start.getFullYear()) { 
						d = new Date(years[0], start.getMonth() + 1, 0); // last day of new month
					
						if (start.getDate() > d.getDate()) { start.setDate(d.getDate()); }
	
						start.setYear(years[0]); 
					}
					
					if (years.getLast() < end.getFullYear()) { 
						d = new Date(years.getLast(), end.getMonth() + 1, 0); // last day of new month
					
						if (end.getDate() > d.getDate()) { end.setDate(d.getDate()); }
	
						end.setYear(years.getLast());
					}		
				}
	
				if (el.format.test('(F|m|M|n)')) { // search for a month select
					var months_start = [];
					var months_end = [];

					el.getChildren().each(function(option) { // get options
						var values = this.unformat(option.value, el.format);
	
						if ($type(values[0]) != 'number' || values[0] == years[0]) { // if it's a year / month combo for curr year, or simply a month select
							if (!months_start.contains(values[1])) { months_start.push(values[1]); } // add to months array
						}
	
						if ($type(values[0]) != 'number' || values[0] == years.getLast()) { // if it's a year / month combo for curr year, or simply a month select
							if (!months_end.contains(values[1])) { months_end.push(values[1]); } // add to months array
						}
					}, this);
	
					months_start.sort(this.sort);
					months_end.sort(this.sort);
					
					if (months_start[0] > start.getMonth()) { 
						d = new Date(start.getFullYear(), months_start[0] + 1, 0); // last day of new month
					
						if (start.getDate() > d.getDate()) { start.setDate(d.getDate()); }
	
						start.setMonth(months_start[0]); 
					}
					
					if (months_end.getLast() < end.getMonth()) { 
						d = new Date(start.getFullYear(), months_end.getLast() + 1, 0); // last day of new month
					
						if (end.getDate() > d.getDate()) { end.setDate(d.getDate()); }
	
						end.setMonth(months_end.getLast());
					}		
				}
			}
		}, this);
		
		return { 'start': start, 'end': end };
	},


	// caption: returns the caption element with header and navigation
	// @param cal (obj)
	// @returns caption (element)

	caption: function(cal) {
		// start by assuming navigation is allowed
		var navigation = {
			prev: { 'month': true, 'year': true },
			next: { 'month': true, 'year': true }
		};
		
		// if we're in an out of bounds year
		if (cal.year == cal.start.getFullYear()) { 
			navigation.prev.year = false; 
			if (cal.month == cal.start.getMonth() && this.options.navigation == 1) { 
				navigation.prev.month = false;
			}		
		}		
		if (cal.year == cal.end.getFullYear()) { 
			navigation.next.year = false; 
			if (cal.month == cal.end.getMonth() && this.options.navigation == 1) { 
				navigation.next.month = false;
			}
		}

		// special case of improved navigation but months array with only 1 month we can disable all month navigation
		if ($type(cal.months) == 'array') {
			if (cal.months.length == 1 && this.options.navigation == 2) {
				navigation.prev.month = navigation.next.month = false;
			}
		}

		var caption = new Element('caption');

		var prev = new Element('a').addClass(this.classes.prev).appendText('\x3c'); // <		
		var next = new Element('a').addClass(this.classes.next).appendText('\x3e'); // >

		if (this.options.navigation == 2) {
			var month = new Element('span').addClass(this.classes.month).injectInside(caption);
			
			if (navigation.prev.month) { prev.clone().addEvent('click', function(cal) { this.navigate(cal, 'm', -1); }.pass(cal, this)).injectInside(month); }
			
			month.adopt(new Element('span').appendText(this.options.months[cal.month]));

			if (navigation.next.month) { next.clone().addEvent('click', function(cal) { this.navigate(cal, 'm', 1); }.pass(cal, this)).injectInside(month); }

			var year = new Element('span').addClass(this.classes.year).injectInside(caption);

			if (navigation.prev.year) { prev.clone().addEvent('click', function(cal) { this.navigate(cal, 'y', -1); }.pass(cal, this)).injectInside(year); }
			
			year.adopt(new Element('span').appendText(cal.year));

			if (navigation.next.year) { next.clone().addEvent('click', function(cal) { this.navigate(cal, 'y', 1); }.pass(cal, this)).injectInside(year); }
		}
		else { // 1 or 0
			if (navigation.prev.month && this.options.navigation) { prev.clone().addEvent('click', function(cal) { this.navigate(cal, 'm', -1); }.pass(cal, this)).injectInside(caption); }

			caption.adopt(new Element('span').addClass(this.classes.month).appendText(this.options.months[cal.month]));
			
			caption.adopt(new Element('span').addClass(this.classes.year).appendText(cal.year));
			
			if (navigation.next.month && this.options.navigation) { next.clone().addEvent('click', function(cal) { this.navigate(cal, 'm', 1); }.pass(cal, this)).injectInside(caption); }

		}

		return caption;
	},


	// changed: run when a select value is changed
	// @param cal (obj)

	changed: function(cal) {
		cal.val = this.read(cal); // update calendar val from inputs	

		$extend(cal, this.values(cal)); // update bounds - based on curr month

		this.rebuild(cal); // rebuild days select

		if (!cal.val) { return; } // in case the same date was clicked the cal has no set date we should exit		

		if (cal.val.getDate() < cal.days[0]) { cal.val.setDate(cal.days[0]); }
		if (cal.val.getDate() > cal.days.getLast()) { cal.val.setDate(cal.days.getLast()); }
		
		cal.els.each(function(el) {	// then we can set the value to the field
			el.value = this.format(cal.val, el.format); 		
		}, this);
		
		this.check(cal); // checks other cals

		this.calendars.each(function(kal) { // update cal graphic if visible
			if (kal.visible) { this.display(kal); }
		}, this);
	},


	// check: checks other calendars to make sure no overlapping values
	// @param cal (obj)

	check: function(cal) {
		this.calendars.each(function(kal, i) {
			if (kal.val) { // if calendar has value set
				var change = false;
			
				if (i < cal.id) { // preceding calendar
					var bound = new Date(Date.parse(cal.val));
					
					bound.setDate(bound.getDate() - (this.options.pad * (cal.id - i)));

					if (bound < kal.val) { change = true; }
				}
				if (i > cal.id) { // following calendar
					var bound = new Date(Date.parse(cal.val));
					
					bound.setDate(bound.getDate() + (this.options.pad * (i - cal.id)));
					
					if (bound > kal.val) { change = true; }
				}

				if (change) {
					if (kal.start > bound) { bound = kal.start; }
					if (kal.end < bound) { bound = kal.end; }

					kal.month = bound.getMonth();
					kal.year = bound.getFullYear();		

					$extend(kal, this.values(kal));			

					// TODO - IN THE CASE OF SELECT MOVE TO NEAREST VALID VALUE
					// IN THE CASE OF INPUT DISABLE

					// if new date is not valid better unset cal value
					// otherwise it would mean incrementally checking to find the nearest valid date which could be months / years away
					kal.val = kal.days.contains(bound.getDate()) ? bound : null;

					this.write(kal);

					if (kal.visible) { this.display(kal); } // update cal graphic if visible
				}
			}
			else {
				kal.month = cal.month;
				kal.year = cal.year;
			}
		}, this);
	},
	

	// clicked: run when a valid day is clicked in the calendar
	// @param cal (obj)

	clicked: function(td, day, cal) {
		cal.val = (this.value(cal) == day) ? null : new Date(cal.year, cal.month, day); // set new value - if same then disable

		this.write(cal); 

		// ok - in the special case that it's all selects and there's always a date no matter what (at least as far as the form is concerned)
		// we can't let the calendar undo a date selection - it's just not possible!!
		if (!cal.val) { cal.val = this.read(cal); }

		if (cal.val) {
			this.check(cal); // checks other cals						
			this.toggle(cal); // hide cal
		} 
		else { // remove active class and replace with valid
			td.addClass(this.classes.valid);
			td.removeClass(this.classes.active);
		}
	},
	

	// display: create calendar element
	// @param cal (obj)

	display: function(cal) {
		// 1. header and navigation
		this.calendar.empty(); // init div

		this.calendar.className = this.classes.calendar + ' ' + this.options.months[cal.month].toLowerCase();

		var div = new Element('div').injectInside(this.calendar); // a wrapper div to help correct browser css problems with the caption element

		var table = new Element('table').injectInside(div).adopt(this.caption(cal));
				
		// 2. day names		
		var thead = new Element('thead').injectInside(table);

		var tr = new Element('tr').injectInside(thead);
		
		for (var i = 0; i <= 6; i++) {
			var th = this.options.days[(i + this.options.offset) % 7];
			
			tr.adopt(new Element('th', { 'title': th }).appendText(th.substr(0, 1)));
		}

		// 3. day numbers
		var tbody = new Element('tbody').injectInside(table);
		var tr = new Element('tr').injectInside(tbody);

		var d = new Date(cal.year, cal.month, 1);
		var offset = ((d.getDay() - this.options.offset) + 7) % 7; // day of the week (offset)
		var last = new Date(cal.year, cal.month + 1, 0).getDate(); // last day of this month
		var prev = new Date(cal.year, cal.month, 0).getDate(); // last day of previous month
		var active = this.value(cal); // active date (if set and within curr month)
		var valid = cal.days; // valid days for curr month
		var inactive = []; // active dates set by other calendars
		var hilited = [];
		this.calendars.each(function(kal, i) {
			if (kal != cal && kal.val) {
				if (cal.year == kal.val.getFullYear() && cal.month == kal.val.getMonth()) { inactive.push(kal.val.getDate()); }

				if (cal.val) {
					for (var day = 1; day <= last; day++) {
						d.setDate(day);
						
						if ((i < cal.id && d > kal.val && d < cal.val) || (i > cal.id && d > cal.val && d < kal.val)) { 
							if (!hilited.contains(day)) { hilited.push(day); }
						}
					}
				}
			}
		}, this);
		var d = new Date();
		var today = new Date(d.getFullYear(), d.getMonth(), d.getDate()).getTime(); // today obv 
		
		for (var i = 1; i < 43; i++) { // 1 to 42 (6 x 7 or 6 weeks)
			if ((i - 1) % 7 == 0) { tr = new Element('tr').injectInside(tbody); } // each week is it's own table row

			var td = new Element('td').injectInside(tr);
						
			var day = i - offset;
			var date = new Date(cal.year, cal.month, day);
			
			var cls = '';
			
			if (day === active) { cls = this.classes.active; } // active
			else if (inactive.contains(day)) { cls = this.classes.inactive; } // inactive
			else if (valid.contains(day)) { cls = this.classes.valid; } // valid
			else if (day >= 1 && day <= last) { cls = this.classes.invalid; } // invalid

			if (date.getTime() == today) { cls = cls + ' ' + this.classes.today; } // adds class for today

			if (hilited.contains(day)) { cls = cls + ' ' + this.classes.hilite; } // adds class if hilited

			td.addClass(cls);

			if (valid.contains(day)) { // if it's a valid - clickable - day we add interaction
				td.setProperty('title', this.format(date, 'D M jS Y'));
				
				td.addEvents({
					'click': function(td, day, cal) { 
						this.clicked(td, day, cal); 
					}.pass([td, day, cal], this),
					'mouseover': function(td, cls) { 
						td.addClass(cls); 
					}.pass([td, this.classes.hover]),
					'mouseout': function(td, cls) { 
						td.removeClass(cls); 
					}.pass([td, this.classes.hover])
				});
			}

			// pad calendar with last days of prev month and first days of next month
			if (day < 1) { day = prev + day; }
			else if (day > last) { day = day - last; }

			td.appendText(day);
		}
	},


	// element: helper function
	// @param el (string) element id
	// @param f (string) format string
	// @param cal (obj)

	element: function(el, f, cal) {
		if ($type(f) == 'object') { // in the case of multiple inputs per calendar
			for (var i in f) { 
				if (!this.element(i, f[i], cal)) { return false; }		
			}
			
			return true;
		}

		el = $(el);

		if (!el) { return false; }
		
		el.format = f;
		
		if (el.get('tag') == 'select') { // select elements allow the user to manually set the date via select option
			el.addEvent('change', function(cal) { this.changed(cal); }.pass(cal, this));
		}
		else { // input (type text) elements restrict the user to only setting the date via the calendar
			el.readOnly = true;
			el.addEvent('focus', function(cal) { this.toggle(cal); }.pass(cal, this));
		}

		cal.els.push(el);

		return true;
	},


	// format: formats a date object according to passed in instructions
	// @param date (obj)
	// @param f (string) any combination of punctuation / separators and d, j, D, l, S, m, n, F, M, y, Y
	// @returns string

	format: function(date, format) {
		var str = '';
	
		// Safog.com Datumsformat hier setzen (nicht auswerten) BOF
		if(( format == '' || format == 'undefined' ) && this.m_strDateFormat ){
			format = this.m_strDateFormat;
		}
		// Safog.com Datumsformat hier setzen (nicht auswerten) BOF
		
		if (date) {
			var j = date.getDate(); // 1 - 31
      var w = date.getDay(); // 0 - 6
			var l = this.options.days[w]; // Sunday - Saturday
			var n = date.getMonth() + 1; // 1 - 12
			var f = this.options.months[n - 1]; // January - December
			var y = date.getFullYear() + ''; // 19xx - 20xx
			
			for (var i = 0, len = format.length; i < len; i++) {
				var cha = format.charAt(i); // format char
				
				switch(cha) {
					// year cases
					case 'y': // xx - xx
						y = y.substr(2);
					case 'Y': // 19xx - 20xx
						str += y;
						break;
	
					// month cases
					case 'm': // 01 - 12
						if (n < 10) { n = '0' + n; }
					case 'n': // 1 - 12
						str += n;
						break;
	
					case 'M': // Jan - Dec
						f = f.substr(0, 3);
					case 'F': // January - December
						str += f;
						break;
	
					// day cases
					case 'd': // 01 - 31
						if (j < 10) { j = '0' + j; }
					case 'j': // 1 - 31
						str += j;
						break;
	
					case 'D': // Sun - Sat
						l = l.substr(0, 3);
					case 'l': // Sunday - Saturday
						str += l;
						break;
	
					case 'N': // 1 - 7
						w += 1;
					case 'w': // 0 - 6
						str += w;
						break;

					case 'S': // st, nd, rd or th (works well with j)
						if (j % 10 == 1 && j != '11') { str += 'st'; }
						else if (j % 10 == 2 && j != '12') { str += 'nd'; }
						else if (j % 10 == 3 && j != '13') { str += 'rd'; }
						else { str += 'th'; }
						break;
	
					default:
						str += cha;
				}
			}
		}

	  return str; //  return format with values replaced
	},


	// navigate: calendar navigation
	// @param cal (obj)
	// @param type (str) m or y for month or year
	// @param n (int) + or - for next or prev

	navigate: function(cal, type, n) {
		switch (type) {
			case 'm': // month
					if ($type(cal.months) == 'array') {
						var i = cal.months.indexOf(cal.month) + n; // index of current month
						
						if (i < 0 || i == cal.months.length) { // out of range
							if (this.options.navigation == 1) { // if type 1 nav we'll need to increment the year
								this.navigate(cal, 'y', n);		
							}
		
							i = (i < 0) ? cal.months.length - 1 : 0;
						}

						cal.month = cal.months[i];
					}
					else { 
						var i = cal.month + n;
		
						if (i < 0 || i == 12) {
							if (this.options.navigation == 1) {
								this.navigate(cal, 'y', n);	
							}
		
							i = (i < 0) ? 11 : 0;
						}
						
						cal.month = i;
					}		
					break;

				case 'y': // year
					if ($type(cal.years) == 'array') {
						var i = cal.years.indexOf(cal.year) + n;

						cal.year = cal.years[i]; 
					}
					else { 
						cal.year += n;
					}						
					break;		
		}

		$extend(cal, this.values(cal));

		if ($type(cal.months) == 'array') { // if the calendar has a months select
			var i = cal.months.indexOf(cal.month); // and make sure the curr months exists for the new year

			if (i < 0) { cal.month = cal.months[0]; } // otherwise we'll reset the month
		}

		this.display(cal);
	},


	// read: compiles cal value based on array of inputs passed in
	// @param cal (obj)
	// @returns date (obj) or (null)

	read: function(cal) {
		var arr = [null, null, null];

		cal.els.each(function(el) {
			// returns an array which may contain empty values
			var values = this.unformat(el.value, el.format);
			
			values.each(function(val, i) { 
				if ($type(val) == 'number') { arr[i] = val; }
			}); 
		}, this);

		// we can update the cals month and year values
		if ($type(arr[0]) == 'number') { cal.year = arr[0]; }
		if ($type(arr[1]) == 'number') { cal.month = arr[1]; }

		var val = null;

		if (arr.every(function(i) { return $type(i) == 'number'; })) { // if valid date
			var last = new Date(arr[0], arr[1] + 1, 0).getDate(); // last day of month

			if (arr[2] > last) { arr[2] = last; } // make sure we stay within the month (ex in case default day of select is 31 and month is feb)
			
			val = new Date(arr[0], arr[1], arr[2]);
		}

		//return (cal.val == val) ? null : val; // if new date matches old return null (same date clicked twice = disable)
		return val;
	},

	
	// rebuild: rebuilds days + months selects
	// @param cal (obj)

	rebuild: function(cal) {
		cal.els.each(function(el) {			
			/*
			if (el.get('tag') == 'select' && el.format.test('^(F|m|M|n)$')) { // special case for months-only select
				if (!cal.options) { cal.options = el.clone(); } // clone a copy of months select
			
				var val = (cal.val) ? cal.val.getMonth() : el.value.toInt();

				el.empty(); // initialize select

				cal.months.each(function(month) {
					// create an option element
					var option = new Element('option', {
						'selected': (val == month),
						'value': this.format(new Date(1, month, 1), el.format);
					}).appendText(day).injectInside(el);
				}, this);
			}
			*/

			if (el.get('tag') == 'select' && el.format.test('^(d|j)$')) { // special case for days-only select
				var d = this.value(cal);

				if (!d) { d = el.value.toInt(); } // if the calendar doesn't have a set value, try to use value from select

				el.empty(); // initialize select

				cal.days.each(function(day) {
					// create an option element
					var option = new Element('option', {
						'selected': (d == day),
						'value': ((el.format == 'd' && day < 10) ? '0' + day : day)
					}).appendText(day).injectInside(el);
				}, this);
			}
		}, this); 
	},


	// sort: helper function for numerical sorting

	sort: function(a, b) {
		return a - b;
	},


	// toggle: show / hide calendar 
	// @param cal (obj)

	toggle: function(cal) {
		document.removeEvent('mousedown', this.fn); // always remove the current mousedown script first
			
		if (cal.visible) { // simply hide curr cal						
			cal.visible = false;
			cal.button.removeClass(this.classes.active); // active
			
			this.fx.start('opacity', 1, 0);
		}
		else { // otherwise show (may have to hide others)
			// hide cal on out-of-bounds click
			this.fn = function(e, cal) { 
				var e = new Event(e);
			
				var el = e.target;

				var stop = false;
				
				while (el != document.body && el.nodeType == 1) {
					if (el == this.calendar) { stop = true; }
					this.calendars.each(function(kal) {
						if (kal.button == el || kal.els.contains(el)) { stop = true; }
					});

					if (stop) { 
						e.stop();
						return false;
					}
					else { el = el.parentNode; }
				}
				
				this.toggle(cal);
			}.create({ 'arguments': cal, 'bind': this, 'event': true });				

			document.addEvent('mousedown', this.fn);

			this.calendars.each(function(kal) {
				if (kal == cal) {
					kal.visible = true;
					kal.button.addClass(this.classes.active); // css c-icon-active
				}
				else {
					kal.visible = false;
					kal.button.removeClass(this.classes.active); // css c-icon-active
				}
			}, this);
			
			var size = window.getScrollSize();
			var coord = cal.button.getCoordinates();
			
			// Safog.com: ggf. anderes Element zum Ermitteln der Scroll-Werte benutzen BOF
			if( this.options.strRelScrollID != '' ){
				// Scrolldaten vom Bezugselement holen
				var nScroll = $( this.options.strRelScrollID ).getScroll();
				
				// Button-Koordinaten an Bezugselement zum Ermitteln wie weit gescrollt wurde anpassen
				var x = ( coord.right - nScroll.x ) + this.options.tweak.x;
				var y = ( coord.top - nScroll.y ) + this.options.tweak.y;
			}
			else {
				// Bezugselement ist window, daher stimmen die Button-Koordinaten coord
				var x = coord.right + this.options.tweak.x;
				var y = coord.top + this.options.tweak.y;
			}
			
			// Safog.com: ggf. anderes Element zum Ermitteln der Scroll-Werte benutzen EOF

			// make sure the calendar doesn't open off screen
			if (!this.calendar.coord) { this.calendar.coord = this.calendar.getCoordinates(); }

			if (x + this.calendar.coord.width > size.x) { x -= (x + this.calendar.coord.width - size.x); }
			if (y + this.calendar.coord.height > size.y) { y -= (y + this.calendar.coord.height - size.y); }
			
			this.calendar.setStyles({ left: x + 'px', top: y + 'px' });

			if (window.ie6) { 
				this.iframe.setStyles({ height: this.calendar.coord.height + 'px', left: x + 'px', top: y + 'px', width: this.calendar.coord.width + 'px' }); 
			}
			
			// Safog.com BOF: hier auch die Werte holen, damit die valid-days für den 2.ten 
			// Kalender auch bei selektierten Folgemonat stimmen
			$extend(cal, this.values(cal));
			// Safog.com EOF
			
			this.display(cal);
			
			this.fx.start('opacity', 0, 1);
		}
	},


	// unformat: takes a value from an input and parses the d, m and y elements
	// @param val (string)
	// @param f (string) any combination of punctuation / separators and d, j, D, l, S, m, n, F, M, y, Y
	// @returns array
	
	unformat: function(val, f) {
		// Safog.com Datumsformat hier setzen (nicht auswerten) BOF
		if( ( f == '' || f == 'undefined' ) && this.m_strDateFormat ){
			f = this.m_strDateFormat;
		}
		// Safog.com Datumsformat hier setzen (nicht auswerten) BOF
		
		f = f.escapeRegExp();
		
		var re = {
			d: '([0-9]{2})',
			j: '([0-9]{1,2})',
			D: '(' + this.options.days.map(function(day) { return day.substr(0, 3); }).join('|') + ')',					
			l: '(' + this.options.days.join('|') + ')',
			S: '(st|nd|rd|th)',
			F: '(' + this.options.months.join('|') + ')',
			m: '([0-9]{2})',
			M: '(' + this.options.months.map(function(month) { return month.substr(0, 3); }).join('|') + ')',					
			n: '([0-9]{1,2})',
			Y: '([0-9]{4})',
			y: '([0-9]{2})'
		}

		var arr = []; // array of indexes

		var g = '';

		// convert our format string to regexp
		for (var i = 0; i < f.length; i++) {
			var c = f.charAt(i);
			
			if (re[c]) {
				arr.push(c);

				g += re[c];
			}
			else {
				g += c;
			}
		}

		// match against date
		var matches = val.match('^' + g + '$');
		
		var dates = new Array(3);

		if (matches) {
			matches = matches.slice(1); // remove first match which is the date

			arr.each(function(c, i) {
				i = matches[i];
				
				switch(c) {
					// year cases
					case 'y':
						i = '19' + i; // 2 digit year assumes 19th century (same as JS)
					case 'Y':
						dates[0] = i.toInt();
						break;

					// month cases
					case 'F':
						i = i.substr(0, 3);
					case 'M':
						i = this.options.months.map(function(month) { return month.substr(0, 3); }).indexOf(i) + 1;
					case 'm':
					case 'n':
						dates[1] = i.toInt() - 1;
						break;

					// day cases
					case 'd':
					case 'j':
						dates[2] = i.toInt();
						break;
				}
			}, this);
		}

		return dates;
	},


	// value: returns day value of calendar if set
	// @param cal (obj)
	// @returns day (int) or null

	value: function(cal) {
		var day = null;

		if (cal.val) {
			if (cal.year == cal.val.getFullYear() && cal.month == cal.val.getMonth()) { day = cal.val.getDate(); }
		}

		return day;
	},
	

	// values: returns the years, months (for curr year) and days (for curr month and year) for the calendar
	// @param cal (obj)
	// @returns obj	

	values: function(cal) {
		var years, months, days;

		cal.els.each(function(el) {	
			if (el.get('tag') == 'select') {		
				if (el.format.test('(y|Y)')) { // search for a year select
					years = [];

					el.getChildren().each(function(option) { // get options
						var values = this.unformat(option.value, el.format);
	
						if (!years.contains(values[0])) { years.push(values[0]); } // add to years array
					}, this);
	
					years.sort(this.sort);
				}
	
				if (el.format.test('(F|m|M|n)')) { // search for a month select
					months = []; // 0 - 11 should be

					el.getChildren().each(function(option) { // get options
						var values = this.unformat(option.value, el.format);
	
						if ($type(values[0]) != 'number' || values[0] == cal.year) { // if it's a year / month combo for curr year, or simply a month select
							if (!months.contains(values[1])) { months.push(values[1]); } // add to months array
						}
					}, this);
	
					months.sort(this.sort);
				}
				
				if (el.format.test('(d|j)') && !el.format.test('^(d|j)$')) { // search for a day select, but NOT a days only select
					days = []; // 1 - 31
					
					el.getChildren().each(function(option) { // get options
						var values = this.unformat(option.value, el.format);

						// in the special case of days we dont want the value if its a days only select
						// otherwise that will screw up the options rebuilding
						// we will take the values if they are exact dates though
						if (values[0] == cal.year && values[1] == cal.month) {
							if (!days.contains(values[2])) { days.push(values[2]); } // add to days array
						}
					}, this);
				}
			}
		}, this);
		
		// we start with what would be the first and last days were there no restrictions
		var first = 1;
		var last = new Date(cal.year, cal.month + 1, 0).getDate(); // last day of the month
		
		// if we're in an out of bounds year
		if (cal.year == cal.start.getFullYear()) {
			// in the special case of improved navigation but no months array, we'll need to construct one
			if (months == null && this.options.navigation == 2) {
				months = [];
				
				for (var i = 0; i < 12; i ++) { 
					if (i >= cal.start.getMonth()) { months.push(i); } 
				}
			}
			
			// if we're in an out of bounds month
			if (cal.month == cal.start.getMonth()) { 
				first = cal.start.getDate(); // first day equals day of bound
			}
		}		
		if (cal.year == cal.end.getFullYear()) {
			// in the special case of improved navigation but no months array, we'll need to construct one
			if (months == null && this.options.navigation == 2) {
				months = [];
				
				for (var i = 0; i < 12; i ++) { 
					if (i <= cal.end.getMonth()) { months.push(i); } 
				}
			}

			if (cal.month == cal.end.getMonth()) { 
				last = cal.end.getDate(); // last day equals day of bound
			}
		}

		// let's get our invalid days
		var blocked = this.blocked(cal);

		// finally we can prepare all the valid days in a neat little array
		if ($type(days) == 'array') { // somewhere there was a days select
			days = days.filter(function(day) {
				if (day >= first && day <= last && !blocked.contains(day)) { return day; }
			});
		}
		else { // no days select we'll need to construct a valid days array
			days = [];
			
			for (var i = first; i <= last; i++) { 
				if (!blocked.contains(i)) { days.push(i); }
			}
		}		

		days.sort(this.sort); // sorting our days will give us first and last of month

		return { 'days': days, 'months': months, 'years': years };
	},


	// write: sets calendars value to form elements
	// @param cal (obj)

	write: function(cal) {
		this.rebuild(cal);	 // in the case of options, we'll need to make sure we have the correct number of days available
		
		cal.els.each(function(el) {	// then we can set the value to the field
			
			el.value = this.format(cal.val, el.format);
					
		}, this);
	}
});

Calendar.implement(new Events, new Options);