var allMonth=[31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
var allNameOfWeekDays=["Mon","Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
var allNameOfMonths=["January","February","March","April"," May "," Jun "," July "," August "," September "," October "," November "," December"];
var newDate=new Date();
var yearZero=newDate.getFullYear();
var monthZero=newDate.getMonth();
var day=newDate.getDate();
var currentDay=0, currentDayZero=0;
var month=monthZero, year=yearZero;
var yearMin=2010, yearMax=2015;
var target='';
var hoverEle=false;
function setTarget(e){
	if(e) return e.target;
	if(event) return event.srcElement;
}
function newElement(type, attrs, content, toNode) {
	var ele=document.createElement(type);
	if(attrs) {
		for(var i=0; i<attrs.length; i++) {
			eval('ele.'+attrs[i][0]+(attrs[i][2] ? '=\u0027' :'=')+attrs[i][1]+(attrs[i][2] ? '\u0027' :''));
		}
	}
	if(content) ele.appendChild(document.createTextNode(content));
	if(toNode) toNode.appendChild(ele);
	return ele;
}
function setMonth(ele){month=parseInt(ele.value);calender()}
function setYear(ele){year=parseInt(ele.value);calender()}
function setValue(ele) {
	if(ele.parentNode.className=='week' && ele.firstChild){
		var dayOut=ele.firstChild.nodeValue;
		if(dayOut < 10) dayOut='0'+dayOut;
		var monthOut=month+1;
		if(monthOut < 10) monthOut='0'+monthOut;
		target.value=dayOut+'/'+monthOut+'/'+year;
		removeCalender();
	}
}
function removeCalender() {
	var parentEle=document.getElementById("calender");
	while(parentEle.firstChild) parentEle.removeChild(parentEle.firstChild);
	document.getElementById('basis').parentNode.removeChild(document.getElementById('basis'));
}		
function calender() {
	var parentEle=document.getElementById("calender");
	parentEle.onmouseover=function(e) {
		var ele=setTarget(e);
		if(ele.parentNode.className=='week' && ele.firstChild && ele!=hoverEle) {
			if(hoverEle) hoverEle.className=hoverEle.className.replace(/hoverEle ?/,'');
			hoverEle=ele;
			ele.className='hoverEle '+ele.className;
		} else {
			if(hoverEle) {
				hoverEle.className=hoverEle.className.replace(/hoverEle ?/,'');
				hoverEle=false;
			}
		}
	}
	while(parentEle.firstChild) parentEle.removeChild(parentEle.firstChild);
	function check(){
		if(year%4==0&&(year%100!=0||year%400==0))allMonth[1]=29;
		else allMonth[1]=28;
	}
	function addClass (name) { if(!currentClass){currentClass=name} else {currentClass+=' '+name} };
	if(month < 0){month+=12; year-=1}
	if(month > 11){month-=12; year+=1}
	if(year==yearMax-1) yearMax+=1;
	if(year==yearMin) yearMin-=1;
	check();
	var control=newElement('p',[['id','control',1]],false,parentEle);
	var controlPlus=newElement('a', [['href','javascript:month--;calender()',1],['className','controlPlus',1]], '<', control);
	var select=newElement('select', [['onchange',function(){setMonth(this)}]], false, control);
	for(var i=0; i<allNameOfMonths.length; i++) newElement('option', [['value',i,1]], allNameOfMonths[i], select);
	select.selectedIndex=month;
	select=newElement('select', [['onchange',function(){setYear(this)}]], false, control);
	for(var i=yearMin; i<yearMax; i++) newElement('option', [['value',i,1]], i, select);
	select.selectedIndex=year-yearMin;
	controlPlus=newElement('a', [['href','javascript:month++;calender()',1],['className','controlPlus',1]], '>', control);
	check();
	currentDay=1-new Date(year,month,1).getDay();
	if(currentDay > 0) currentDay-=7;
	currentDayZero=currentDay;
	var newMonth=newElement('table',[['cellSpacing',0,1],['onclick',function(e){setValue(setTarget(e))}]], false, parentEle);
	var newMonthBody=newElement('tbody', false, false, newMonth);
	var tr=newElement('tr', [['className','head',1]], false, newMonthBody);
	tr=newElement('tr', [['className','weekdays',1]], false, newMonthBody);
	for(i=0;i<7;i++) td=newElement('td', false, allNameOfWeekDays[i], tr);	
	tr=newElement('tr', [['className','week',1]], false, newMonthBody);

	for(i=0; i<allMonth[month]-currentDayZero; i++){
		var currentClass=false;			
		currentDay++;
		if(currentDay==day && month==monthZero && year==yearZero) addClass ('today');
		if(currentDay <= 0 ) {
			if(currentDayZero!=-7) td=newElement('td', false, false, tr);
		}
		else {
			if((currentDay-currentDayZero)%7==0) addClass ('holiday');
			td=newElement('td', (!currentClass ? false : [['className',currentClass,1]] ), currentDay, tr);
			if((currentDay-currentDayZero)%7==0) tr=newElement('tr', [['className','week',1]], false, newMonthBody);
		}
		if(i==allMonth[month]-currentDayZero-1){
			i++;
			while(i%7!=0){i++;td=newElement('td', false, false, tr)};
		}
	}
}
function showCalender(ele) {
	if(document.getElementById('basis')) { removeCalender() }
	else {
		target=document.getElementById(ele.id.replace(/for_/,'')); 
		var basis=ele.parentNode.insertBefore(document.createElement('div'),ele);
		basis.id='basis';
		newElement('div', [['id','calender',1]], false, basis);
		calender();
	}
}