var monthtext=['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sept','Oct','Nov','Dec'];

function getNumDays(month,year){
var numDays = 31;

switch(month)
{
	case 1: 
	 		if(year%4 == 0) numDays = 29;
	 		else numDays = 28;
	  break;
	case 3: 	  
	case 5: 	  
	case 8: 	  
	case 10: 
	 		numDays = 30;
	  break;
}
return numDays;
}


function getValue(val){
var theVal = "";
if (val<10)
{
	theVal = "0" + val;
}
else theVal = val;
return theVal;
}


function getNum(num){
var theNum;
if(num.substring(0,1) =="0") theNum = parseInt(num.substring(1));
	else theNum = parseInt(num);
return theNum;
}


function getYearValue(year){
var theVal = ""+year;
return theVal.substring(2);
}


function populatedropdown(dayfield, monthfield, yearfield,day,month,year){

var dayfield=document.getElementById(dayfield);
var monthfield=document.getElementById(monthfield);
var yearfield=document.getElementById(yearfield);
var numDays = getNumDays(getNum(month)-1,getNum(year));




for (var i=0; i<numDays; i++)
dayfield.options[i]=new Option(i+1, getValue(i+1));

dayfield.options[getNum(day)-1]=new Option(getNum(day), day, true, true);
for (var m=0; m<12; m++)
monthfield.options[m]=new Option(monthtext[m], getValue(m+1));
monthfield.options[getNum(month)-1]=new Option(monthtext[getNum(month)-1], getValue(month), true, true);
var today = new Date();
var thisyear=2000;
for (var y=0; y<20; y++){
yearfield.options[y]=new Option(thisyear, getYearValue(thisyear));
thisyear+=1;
}
yearfield.options[getNum(year)]=new Option("20"+year, year, true, true);

}



function updateDay(dayfield,monthfield,yearfield){
	var dayfield=document.getElementById(dayfield);
	var monthfield=document.getElementById(monthfield);
	var yearfield = document.getElementById(yearfield);


	var month = getNum(monthfield.value);
	var year = getNum(yearfield.value);

	var numDays = getNumDays(month-1,year);

	if(dayfield.options.length<numDays)
	{
	
		var i = dayfield.options.length;
		while(i<numDays)
		{		
			dayfield.options[i] = new Option(i+1,getValue(i+1));
			i++;
		}	
	}
	else if(dayfield.options.length>numDays)
	{
		var i = dayfield.options.length;
		while(i>numDays)
		{				
			i--;	
			dayfield.options[i] = null;			
		}
	}	
	
}





function populateTime(hourdropdown,minutedropdown,hour,minute){
	var hourfield=document.getElementById(hourdropdown);
	var minutefield=document.getElementById(minutedropdown);
	
	for (var i = 0; i < 24; i++) {
		if(i<9){ var text = "0"+(i+1); } else var text = (i+1);
		if(i == (hour-1)) hourfield.options[i] = new Option(text, text,true,true);
		else hourfield.options[i] = new Option(text, text);
	}
	
	for (var i = 0; i < 60; i++) {
		if(i<10){ var text = "0"+i; } else var text = i;
		if(i == (minute)) minutefield.options[i] = new Option(text, text,true,true);
		else minutefield.options[i] = new Option(text,text);
	}
	
}