/*
the variables nameDdlYear, nameDdlMonth, nameDdlDay
are initialized in CodeBehind

*/

function checkDate()
{
	var days = GetMonthDays(document.getElementById(nameDdlMonth).value)
	fillDays(days);
}

function CheckForLeapYear(year)
{
if ((year % 4 == 0 || year % 100 == 0) && year % 400 != 0) 
	{
		return 'true';
	} else
	{
		return 'false';
	}
}

function GetMonthDays(value)
{
switch(value){
	case '1': return 31;
	break;
	case '2':	{
				if(CheckForLeapYear(document.getElementById(nameDdlYear).value) == 'true') return 29; 
					else return 28;
				}
	break;
	case '3': return 31;
	break;
	case '4': return 30;
	break;
	case '5': return 31;
	break;
	case '6': return 30;
	break;
	case '7': return 31;
	break;
	case '8': return 31;
	break;
	case '9': return 30;
	break;
	case '10': return 31;
	break;
	case '11': return 30;
	break;
	case '12': return 31;
	break;
	default: return 0;
	break;
	}
}

function fillDays(value)
{
	var selected = document.getElementById(nameDdlDay).selectedIndex;
	var SlaveSize = document.getElementById(nameDdlDay).length;
	for (var i = 0; i <= SlaveSize; i++)
	{
		document.getElementById(nameDdlDay).remove(entry, position);
	}
	var d_value = 1;
	var position = null;
	for (var i = 1; i <= value; i++)
	{
		if (document.all) position = document.getElementById(nameDdlDay).length;
		var entry = document.createElement('option');
		entry.text = i;
		entry.value = d_value;
		d_value++;
		document.getElementById(nameDdlDay).add(entry, position);
	}
	document.getElementById(nameDdlDay).selectedIndex = selected;
}