function Epoch(name,mode,targetelement,multiselect) {

	var self = this;

	function calConfig() {

		self.versionNumber = '2.0.1';

		self.displayYearInitial = self.curDate.getFullYear();

		self.displayMonthInitial = self.curDate.getMonth();

		self.displayYear = self.displayYearInitial;

		self.displayMonth = self.displayMonthInitial;

		self.minDate = new Date(2006,6,1);

		self.maxDate = new Date(self.displayYearInitial+5,6,31);

		self.startDay = 1;

		self.showWeeks = false;

        self.selCurMonthOnly = true;

	}



	function setLang() {

		self.daylist = new Array('Ne','Po','Út','Stř','Čt','Pá','So','Ne','Po','Út','Stř','Čt','Pá','So');

		self.months_sh = new Array('Leden','Únor','Březen','Duben','Květen','Červen','Červenec','Srpen','Září','Říjen','Listopad','Prosinec');

		self.monthup_title = 'Další měsíc';

		self.monthdn_title = 'Předešlý měsíc';

		self.clearbtn_caption = 'Vyčistit';

		self.clearbtn_title = 'Vyčistit označené datum';

		self.maxrange_caption = 'MAximální rozsah';

		self.closebtn_caption = 'Zavřít';

		self.closebtn_title = 'Zavřít';

	}



	function setDays() {

		self.daynames = new Array();

		var j=0;

		for(var i=self.startDay;i<self.startDay + 7;i++) {

			self.daynames[j++] = self.daylist[i];

		}

		self.monthDayCount = new Array(31,((self.curDate.getFullYear() - 2000) % 4 ? 28 : 29),31,30,31,30,31,31,30,31,30,31);

	}



	function createCalendar() {

		var tbody, tr, td;

		self.calendar = document.createElement('table');

		self.calendar.setAttribute('id',self.name+'_calendar');

		setClass(self.calendar,'calendar');

		self.calendar.style.display = 'none';



		addEventHandler(self.calendar,'selectstart', function() {return false;});

		addEventHandler(self.calendar,'drag', function() {return false;});

		tbody = document.createElement('tbody');



		tr = document.createElement('tr');

		td = document.createElement('td');

		td.appendChild(createMainHeading());

		tr.appendChild(td);

		tbody.appendChild(tr);



		tr = document.createElement('tr');

		td = document.createElement('td');

		self.calendar.celltable = document.createElement('table');

		setClass(self.calendar.celltable,'cells');

		self.calendar.celltable.appendChild(createDayHeading());

		self.calendar.celltable.appendChild(createCalCells());

		td.appendChild(self.calendar.celltable);

		tr.appendChild(td);

		tbody.appendChild(tr);



		tr = document.createElement('tr');

		td = document.createElement('td');

		td.appendChild(createFooter());

		tr.appendChild(td);

		tbody.appendChild(tr);



		self.calendar.appendChild(tbody);



		addEventHandler(self.calendar,'mouseover',cal_onmouseover);

		addEventHandler(self.calendar,'mouseout',cal_onmouseout);

	}



	function createMainHeading() {

		var container = document.createElement('div');

		setClass(container,'mainheading');

		self.monthSelect = document.createElement('select');

		self.yearSelect = document.createElement('select');

		var monthDn = document.createElement('input'), monthUp = document.createElement('input');

		var opt, i;

		for(i=0;i<12;i++) {

			opt = document.createElement('option');

			opt.setAttribute('value',i);

			if(self.displayMonth == i) {

				opt.setAttribute('selected','selected');

			}

			opt.appendChild(document.createTextNode(self.months_sh[i]));

			self.monthSelect.appendChild(opt);

		}

		var yrMax = self.maxDate.getFullYear(), yrMin = self.minDate.getFullYear();

		for(i=yrMin;i<=yrMax;i++) {

			opt = document.createElement('option');

			opt.setAttribute('value',i);

			if(self.displayYear == i) {

				opt.setAttribute('selected','selected');

			}

			opt.appendChild(document.createTextNode(i));

			self.yearSelect.appendChild(opt);

		}

		monthUp.setAttribute('type','button');

		monthUp.setAttribute('value','>');

		monthUp.setAttribute('title',self.monthup_title);

		monthDn.setAttribute('type','button');

		monthDn.setAttribute('value','<');

		monthDn.setAttribute('title',self.monthdn_title);

		self.monthSelect.owner = self.yearSelect.owner = monthUp.owner = monthDn.owner = self;



		function selectonchange()	{

			if(self.goToMonth(self.yearSelect.value,self.monthSelect.value)) {

				self.displayMonth = self.monthSelect.value;

				self.displayYear = self.yearSelect.value;

			}

			else {

				self.monthSelect.value = self.displayMonth;

				self.yearSelect.value = self.displayYear;

			}

		}

		addEventHandler(monthUp,'click',function(){self.nextMonth();});

		addEventHandler(monthDn,'click',function(){self.prevMonth();});

		addEventHandler(self.monthSelect,'change',selectonchange);

		addEventHandler(self.yearSelect,'change',selectonchange);



		container.appendChild(monthDn);

		container.appendChild(self.monthSelect);

		container.appendChild(self.yearSelect);

		container.appendChild(monthUp);

		return container;

	}

	function createFooter() {

		var container = document.createElement('div');

		var clearSelected = document.createElement('input');

		clearSelected.setAttribute('type','button');

		clearSelected.setAttribute('value',self.clearbtn_caption);

		clearSelected.setAttribute('title',self.clearbtn_title);

		clearSelected.owner = self;

		addEventHandler(clearSelected,'click',function() {self.resetSelections(false);});

		container.appendChild(clearSelected);

		if(self.mode == 'popup') {

			var closeBtn = document.createElement('input');

			closeBtn.setAttribute('type','button')

			closeBtn.setAttribute('value',self.closebtn_caption);

			closeBtn.setAttribute('title',self.closebtn_title);

			addEventHandler(closeBtn,'click',function(){self.hide();});

			setClass(closeBtn,'closeBtn');

			container.appendChild(closeBtn);

		}

		return container;

	}

	function createDayHeading() {

		self.calHeading = document.createElement('thead');

		setClass(self.calHeading,'caldayheading');

		var tr = document.createElement('tr'), th;

		self.cols = new Array(false,false,false,false,false,false,false);



		if(self.showWeeks) {

			th = document.createElement('th');

			setClass(th,'wkhead');

			tr.appendChild(th);

		}



		for(var dow=0;dow<7;dow++) {

			th = document.createElement('th');

			th.appendChild(document.createTextNode(self.daynames[dow]));

			if(self.selectMultiple) {

				th.headObj = new CalHeading(self,th,(dow + self.startDay < 7 ? dow + self.startDay : dow + self.startDay - 7));

			}

			tr.appendChild(th);

		}

		self.calHeading.appendChild(tr);

		return self.calHeading;

	}



	function createCalCells() {

		self.rows = new Array(false,false,false,false,false,false);

		self.cells = new Array();

		var row = -1, totalCells = (self.showWeeks ? 48 : 42);

		var beginDate = new Date(self.displayYear,self.displayMonth,1);

		var endDate = new Date(self.displayYear,self.displayMonth,self.monthDayCount[self.displayMonth]);

		var sdt = new Date(beginDate);

		sdt.setDate(sdt.getDate() + (self.startDay - beginDate.getDay()) - (self.startDay - beginDate.getDay() > 0 ? 7 : 0) );

		self.calCells = document.createElement('tbody');

		var tr,td;

		var cellIdx = 0, cell, week, dayval;



		for(var i=0;i<totalCells;i++) {

			if(self.showWeeks) {

				if(i % 8 == 0) {

					row++;

					week = sdt.getWeek(self.startDay);

					tr = document.createElement('tr');

					td = document.createElement('td');

					if(self.selectMultiple) {

						td.weekObj = new WeekHeading(self,td,week,row)

					}

					else {

						setClass(td,'wkhead');

					}

					td.appendChild(document.createTextNode(week));

					tr.appendChild(td);

					i++;

				}

			}

			else if(i % 7 == 0) {

				row++;

				week = sdt.getWeek(self.startDay);

				tr = document.createElement('tr');

			}



			dayval = sdt.getDate();

			td = document.createElement('td');

			td.appendChild(document.createTextNode(dayval));

			cell = new CalCell(self,td,sdt,row,week);

			self.cells[cellIdx] = cell;

			td.cellObj = cell;

			tr.appendChild(td);

			self.calCells.appendChild(tr);

			self.reDraw(cellIdx++);

			sdt.setDate(dayval + 1);

		}

		return self.calCells;

	}



	function setMode(targetelement)	{

		if(self.mode == 'popup') { 

			self.calendar.style.position = 'absolute';

		}



		if(targetelement) {

			switch(self.mode) {

				case 'popup':

					self.calendar.style.position = 'absolute';

					document.body.appendChild(self.calendar);

					self.setTarget(targetelement,false);

					break;

			}

		}

		else {

			document.body.appendChild(self.calendar);

			self.visible = false;

		}

	}



	function deleteCells() {

		self.calendar.celltable.removeChild(self.calendar.celltable.childNodes[1]);

	}



	function setClass(element,className) {

		element.setAttribute('class',className);

		element.setAttribute('className',className);

	}



	function setCellProperties(cellindex) {

		var cell = self.cells[cellindex];

		var date;

		idx = self.dateInArray(self.dates,cell.date);

		if(idx > -1) {

			date = self.dates[idx];

			cell.date.selected = date.selected || false;

			cell.date.type = date.type;

			cell.date.canSelect = date.canSelect;

			cell.setTitle(date.title);

			cell.setURL(date.href);

			cell.setHTML(date.cellHTML);

		}

		else {

			cell.date.selected = false;

		}



		if(cell.date.getTime() < self.minDate.getTime() || cell.date.getTime() > self.maxDate.getTime()) {

			cell.date.canSelect = false;

		}

		cell.setClass();

	}



	function cal_onmouseover() {

		self.mousein = true;

	}



	function cal_onmouseout()	{

		self.mousein = false;

	}



	function updateSelectedDates() {

		var idx = 0;

		self.selectedDates = new Array();

		for(i=0;i<self.dates.length;i++) {

			if(self.dates[i].selected) {

				self.selectedDates[idx++] = self.dates[i];

			}

		}

	}

	//PUBLIC METHODS

	self.dateInArray = function(arr,searchVal,startIndex) {

		startIndex = (startIndex != null ? startIndex : 0);

		for(var i=startIndex;i<arr.length;i++) {

			if(searchVal.getUeDay() == arr[i].getUeDay()) {

				return i;

			}

		}

		return -1;

	};

	self.setTarget = function (targetelement, focus)

	{

		if(self.mode == 'popup') {

			function popupFocus() {

				self.show();

			}

			function popupBlur() {

				if(!self.mousein){

					self.hide();

				}

			}

			function popupKeyDown() {

				self.hide();

			}



			if(self.tgt) {

				removeEventHandler(self.tgt,'focus',popupFocus);

				removeEventHandler(self.tgt,'blur',popupBlur);

				removeEventHandler(self.tgt,'keydown',popupKeyDown);

			}



			self.tgt = targetelement;

			var dto = self.tgt.dateObj,pdateArr = new Array;

			if(dto) {

				if(self.tgt.value.length) {

					pdateArr[0] = dto;

				}

				self.goToMonth(dto.getFullYear(),dto.getMonth());

			}

			self.selectDates(pdateArr,true,true,true);



			self.topOffset = self.tgt.offsetHeight;

			self.leftOffset = 0;

			self.updatePos(self.tgt);



			addEventHandler(self.tgt,'focus',popupFocus);

			addEventHandler(self.tgt,'blur',popupBlur);

			addEventHandler(self.tgt,'keydown',popupKeyDown);

			if(focus !== false) {

				popupFocus();

			}

		}

		else { //if this is a flat or inline calendar

			if(self.tgt) {

				self.tgt.removeChild(self.calendar);

			}

			self.tgt = targetelement;

			self.tgt.appendChild(self.calendar);

			self.show();

		}

	};



	self.nextMonth = function () {

		var month = self.displayMonth;

		var year = self.displayYear;



		if(self.displayMonth < 11) {

			month++;

		}

		else if(self.yearSelect.value < self.maxDate.getFullYear()) { //if not, increment the year as well

			month = 0;

			year++;

		}

		return self.goToMonth(year,month);

	};



	self.prevMonth = function () {

		var month = self.displayMonth;

		var year = self.displayYear;



		if(self.displayMonth > 0) {

			month--;

		}

		else {

			month = 11;

			year--;

		}

		return self.goToMonth(year,month);

	};



	self.goToMonth = function (year,month) {

		var testdatemin = new Date(year, month, 31);

		var testdatemax = new Date(year, month, 1);

		if(testdatemin >= self.minDate && testdatemax <= self.maxDate) {

			self.monthSelect.value = self.displayMonth = month;

			self.yearSelect.value = self.displayYear = year;



			createCalCells();

			deleteCells();

			self.calendar.celltable.appendChild(self.calCells);

			return true;

		}

		else {

			alert(self.maxrange_caption);

			return false;

		}

	};



	self.updatePos = function (target) {

		if(self.mode == 'popup') {

			self.calendar.style.top = getTop(target) + self.topOffset + 'px';

			self.calendar.style.left = getLeft(target) + self.leftOffset + 'px';

		}

	};



	self.show = function ()	{

		self.updatePos(self.tgt);

		self.calendar.style.display = 'block';

		self.visible = true;

	};



	self.hide = function () {

		self.calendar.style.display = 'none';

		self.visible = false;

	};

	self.toggle = function () {

		self.visible ? self.hide() : self.show();

	};



	self.selectDates = function (inpdates,selectVal,redraw,removeothers) {

		var i, idx;

		if(removeothers == true) {

			for(i=0;i<self.dates.length;i++) {

				self.dates[i].selected = false;

			}

		}

		for(i=0;i<inpdates.length;i++) {

			idx = self.dateInArray(self.dates,inpdates[i]);

			if(selectVal == true) {

				inpdates[i].selected = true;

				if(idx == -1) {

					self.dates[self.dates.length] = inpdates[i];

				}

				else {

					self.dates[idx].selected = true;

				}

			}

			else {

				if(idx > -1) {

					self.dates[idx].selected = inpdates[i].selected = false;

					if(self.dates[idx].type == 'normal') {

						self.dates.splice(idx,1);

					}

				}

			}

		}



		updateSelectedDates();

		if(redraw != false) {

			self.reDraw();

		}

	};



	self.resetSelections = function (retMonth) {

		var dateArray = new Array();

		var dt = self.dates;

		for(var i=0;i<dt.length;i++) {

			if(dt[i].selected) {

				dateArray[dateArray.length] = dt[i];

			}

		}

		self.selectDates(dateArray,false,false);

		self.rows = new Array(false,false,false,false,false,false,false);

		self.cols = new Array(false,false,false,false,false,false,false);

		if(self.mode == 'popup') { //hide the calendar and clear the input element if in popup mode

			self.tgt.value = '';

			self.hide();

		}

		retMonth == true ? self.goToMonth(self.displayYearInitial,self.displayMonthInitial) : self.reDraw();

	};



	self.reDraw = function (index) {

		self.state = 1;

		var len = index ? index + 1 : self.cells.length;

		for(var i = index || 0;i<len;i++) {

			setCellProperties(i);

		}

		self.state = 2;

	};



	self.getCellIndex = function(date) {

		for(var i=0;i<self.cells.length;i++) {

			if(self.cells[i].date.getUeDay() == date.getUeDay()) {

				return i;

			}

		}

		return -1;

	};



	//begin constructor code:

	//PUBLIC VARIABLES

	self.state = 0;

	self.name = name;

	self.curDate = new Date();

	self.mode = mode;

	self.selectMultiple = (multiselect == true); //'false' if not true or not set at all



	self.dates = new Array();

	self.selectedDates = new Array();



	self.calendar;

	self.calHeading;

	self.calCells;

	self.rows;

	self.cols;

	self.cells = new Array();

	self.monthSelect;

	self.yearSelect;

	self.mousein = false;



	calConfig();

	setLang();

	setDays();

	createCalendar();

	setMode(targetelement);

	self.state = 2; //0: initializing, 1: redrawing, 2: finished!

	self.visible ? self.show() : self.hide();

}

//-----------------------------------------------------------------------------

function CalHeading(owner,tableCell,dayOfWeek) {

	function DayHeadingonclick() {

		var sdates = owner.dates;

		var cells = owner.cells;

		var dateArray = new Array();

		owner.cols[dayOfWeek] = !owner.cols[dayOfWeek];

		for(var i=0;i<cells.length;i++) {

			if(cells[i].dayOfWeek == dayOfWeek && cells[i].date.canSelect && (!owner.selCurMonthOnly || cells[i].date.getMonth() == owner.displayMonth && cells[i].date.getFullYear() == owner.displayYear)) { //if the cell's DoW matches, with other conditions

				dateArray[dateArray.length] = cells[i].date;

			}

		}

		owner.selectDates(dateArray,owner.cols[dayOfWeek],true);

	}



	var self = this;

	self.dayOfWeek = dayOfWeek;

	addEventHandler(tableCell,'mouseup',DayHeadingonclick);

}



function WeekHeading(owner,tableCell,week,tableRow) {

	function weekHeadingonclick() {

		var cells = owner.cells;

		var sdates = owner.dates;

		var dateArray = new Array();

		owner.rows[tableRow] = !owner.rows[tableRow];

		for(var i=0;i<cells.length;i++) {

			if(cells[i].tableRow == tableRow && cells[i].date.canSelect && (!owner.selCurMonthOnly || cells[i].date.getMonth() == owner.displayMonth && cells[i].date.getFullYear() == owner.displayYear)) { //if the cell's DoW matches, with other conditions)

				dateArray[dateArray.length] = cells[i].date;

			}

		}

		owner.selectDates(dateArray,owner.rows[tableRow],true);

	}



	var self = this;

	self.week = week;

	tableCell.setAttribute('class','wkhead');

	tableCell.setAttribute('className','wkhead');

	addEventHandler(tableCell,'mouseup',weekHeadingonclick);

}



function CalCell(owner,tableCell,dateObj,row,week) {

	var self = this;



	function calCellonclick() {

		if(self.date.canSelect) {

			if(owner.selectMultiple == true) {

				owner.selectDates(new Array(self.date),!self.date.selected,false);

				self.setClass();

			}

			else {

				owner.selectDates(new Array(self.date),true,false,true);

				if(owner.mode == 'popup') {

					owner.tgt.value = self.date.dateFormat();

					owner.tgt.dateObj = new Date(self.date);

					owner.hide();

				}

				owner.reDraw();

			}

		}

	}



	function calCellonmouseover() {

		if(self.date.canSelect) {

			tableCell.setAttribute('class',self.cellClass + ' hover');

			tableCell.setAttribute('className',self.cellClass + ' hover');

		}

	}



	function calCellonmouseout() {

		self.setClass();

	}



	self.setClass = function ()

	{

		if(self.date.canSelect !== false) {

			if(self.date.selected) {

				self.cellClass = 'cell_selected';

			}

			else if(owner.displayMonth != self.date.getMonth() ) {

				self.cellClass = 'notmnth';

			}

			else if(self.date.type == 'holiday') {

				self.cellClass = 'hlday';

			}

			else if(self.dayOfWeek > 0 && self.dayOfWeek < 6) {

				self.cellClass = 'wkday';

			}

			else {

				self.cellClass = 'wkend';

			}

		}

		else {

			self.cellClass = 'noselect';

		}



		if(self.date.getUeDay() == owner.curDate.getUeDay()) {

			self.cellClass = self.cellClass + ' curdate';

		}

		tableCell.setAttribute('class',self.cellClass);

		tableCell.setAttribute('className',self.cellClass);

	};





	self.setURL = function(href,type) {

		if(href) {

			if(type == 'js') {

				addEventHandler(self.tableCell,'mousedown',function(){window.location.href = href;});

			}

			else {

				var url = document.createElement('a');

				url.setAttribute('href',href);

				url.appendChild(document.createTextNode(self.date.getDate()));

				self.tableCell.replaceChild(url,self.tableCell.firstChild);

			}

		}

	}



	self.setTitle = function(titleStr) {

		if(titleStr && titleStr.length > 0) {

			self.title = titleStr;

			self.tableCell.setAttribute('title',titleStr);

		}

	};



	self.setHTML = function(html) {

		if(html && html.length > 0) {

			if(self.tableCell.childNodes[1]) {

				self.tableCell.childNodes[1].innerHTML = html;

			}

			else {

				var htmlCont = document.createElement('div');

				htmlCont.innerHTML = html;

				self.tableCell.appendChild(htmlCont);

			}

		}

	};



	self.cellClass;

	self.tableRow = row;

	self.tableCell = tableCell;

	self.date = new Date(dateObj);

	self.date.canSelect = true;

	self.date.type = 'normal';

	self.date.selected = false;

	self.date.cellHTML = '';

	self.dayOfWeek = self.date.getDay();

	self.week = week;



	addEventHandler(tableCell,'click', calCellonclick);

	addEventHandler(tableCell,'mouseover', calCellonmouseover);

	addEventHandler(tableCell,'mouseout', calCellonmouseout);

	self.setClass();

}



Date.prototype.getDayOfYear = function ()

{

	return parseInt((this.getTime() - new Date(this.getFullYear(),0,1).getTime())/86400000 + 1);

};



Date.prototype.getWeek = function (dowOffset) {

	dowOffset = typeof(dowOffset) == 'int' ? dowOffset : 0;

	var newYear = new Date(this.getFullYear(),0,1);

	var day = newYear.getDay() - dowOffset;

	day = (day >= 0 ? day : day + 7);

	var weeknum, daynum = Math.floor((this.getTime() - newYear.getTime() - (this.getTimezoneOffset()-newYear.getTimezoneOffset())*60000)/86400000) + 1;

   	if(day < 4) {

		weeknum = Math.floor((daynum+day-1)/7) + 1;

		if(weeknum > 52) {

			nYear = new Date(this.getFullYear() + 1,0,1);

			nday = nYear.getDay() - dowOffset;

			nday = nday >= 0 ? nday : nday + 7;

			weeknum = nday < 4 ? 1 : 53;

		}

	}

	else {

		weeknum = Math.floor((daynum+day-1)/7);

	}

	return weeknum;

};



Date.prototype.getUeDay = function ()

{

	return parseInt(Math.floor((this.getTime() - this.getTimezoneOffset() * 60000)/86400000)); //must take into account the local timezone

};



Date.prototype.dateFormat = function(format)

{

	if(!format) {

		format = 'd.m.Y';

	}

	LZ = function(x) {return(x < 0 || x > 9 ? '' : '0') + x};

	var result="";

	var i_format=0;

	var c="";

	var token="";

	var y=this.getFullYear().toString();

	var M=this.getMonth()+1;

	var d=this.getDate();

	var E=this.getDay();

	value = {

		Y: y.toString(),

		m: LZ(M),

		d: LZ(d)

	};



	while (i_format < format.length) {

		c=format.charAt(i_format);

		token="";

		while ((format.charAt(i_format)==c) && (i_format < format.length)) {

			token += format.charAt(i_format++);

		}

		if (value[token] != null) { result=result + value[token]; }

		else { result=result + token; }

	}

	return result;

};



function addEventHandler(element, type, func) {

	if(element.addEventListener) {

		element.addEventListener(type,func,false);

	}

	else if (element.attachEvent) {

		element.attachEvent('on'+type,func);

	}

}



function removeEventHandler(element, type, func) {

	if(element.removeEventListener) {

		element.removeEventListener(type,func,false);

	}

	else if (element.attachEvent) {

		element.detachEvent('on'+type,func);

	}

}



function getTop(element) {

	var oNode = element;

	var iTop = 0;



	while(oNode.tagName != 'HTML') {

		iTop += oNode.offsetTop || 0;

		if(oNode.offsetParent) {

			oNode = oNode.offsetParent;

		}

		else {

			break;

		}

	}

	return iTop;

}



function getLeft(element) {

	var oNode = element;

	var iLeft = 0;

	while(oNode.tagName != 'HTML') {

		iLeft += oNode.offsetLeft || 0;

		if(oNode.offsetParent) {

			oNode = oNode.offsetParent;

		}

		else {

			break;

		}

	}

	return iLeft;

}