function DaysInMonth(currmonth,curryear) {

	if (currmonth == 2)
		if ((curryear % 4 != 0) || ((curryear % 100 == 0) && (curryear % 400 != 0)))
			return 28;
		else
			return 29;
	else if ((currmonth <= 7 && currmonth % 2 == 0) || (currmonth >= 8 && currmonth % 2 != 0))
		return 30;			
	else
		return 31;
}

function FillMonths(SelectObj) {

	var months = new Array(12);
	months[0] = 'Januar';
	months[1] = 'Februar';
	months[2] = 'März';
	months[3] = 'April';
	months[4] = 'Mai';
	months[5] = 'Juni';
	months[6] = 'Juli';
	months[7] = 'August';
	months[8] = 'September';
	months[9] = 'Oktober';
	months[10] = 'November';
	months[11] = 'Dezember';
	
	for (var i=0; i<12; i++) {
		SelectObj.options[i] = new Option(months[i],i+1);
	}

	var now = new Date();
	var currmonth = now.getMonth();
	SelectObj.options[currmonth].selected = true;
}

function FillDays(SelectObj) {

	var now = new Date();
	var currmonth = now.getMonth()+1;
	var curryear = now.getYear();
	if(curryear < 2000) curryear+=1900;

	//alert("currmonth :"+currmonth+"curryear :"+curryear);

	var totaldays = DaysInMonth(currmonth,curryear);

	SelectObj.options[0] = new Option(" ");

	for (var i=0; i<totaldays; i++) {
		SelectObj.options[i+1] = new Option(i+1);
	}

	var now = new Date();
	var currdate = now.getDate();
	SelectObj.options[currdate].selected = true;
}

function UpdateDays(SelectObj,currmonth,curryear) {
	//alert("currmonth :"+currmonth+"curryear :"+curryear);	
	var currmonth = currmonth;

	var previousdate = SelectObj.selectedIndex;

	for (var i=SelectObj.length; i>0; i--) {
		SelectObj.options[i] = null;
	}

	var totaldays = DaysInMonth(currmonth,curryear);

	SelectObj.options[0] = new Option(' ');

	for (i=0; i<totaldays; i++) {
		SelectObj.options[i+1] = new Option(i+1);
	}

	if (totaldays - 1 < previousdate)
		SelectObj.options[totaldays].selected = true;
	else
		SelectObj.options[previousdate].selected = true;
}

function UpdateDate(DayObj,MonthObj,YearObj) {
	
	var now = new Date();
	var currday = now.getDate();
	var currmonth = now.getMonth()+1;
	var curryear = now.getYear();
	if(curryear < 2000) curryear+=1900;

	DayObj.options[currday].selected = true;

	for(i=0;i<MonthObj.length;++i)
		if(MonthObj.options[i].value == currmonth)
			MonthObj.options[i].selected = true;

	for(i=0;i<YearObj.length;++i)
		if(YearObj.options[i].value == curryear)
			YearObj.options[i].selected = true;
}

function adjustDays(SelectObj,currmonth) {
	if (SelectObj.value == '')
		SelectObj.selectedIndex = DaysInMonth(currmonth) - 1;
}