var mDays=new Array(12);
mDays[1] = 31; mDays[2] = 28; mDays[3] = 31; mDays[4] = 30; mDays[5] = 31; mDays[6] = 30;
mDays[7] = 31; mDays[8] = 31; mDays[9] = 30; mDays[10] = 31; mDays[11] = 30; mDays[12] = 31;


function MonthChange(obj){
	if (obj){
		var obj_val		= (obj.selectedIndex + 1);
		var obj_id		= obj.id;
		var day_obj		= document.getElementById(obj_id.replace("mm","dd"));
		var day_val		= null;
		
		if(day_obj.options.length>0){
			day_val		= day_obj.options[day_obj.selectedIndex].value;
		}
		
		FillDays(day_obj, obj_val, day_val);
	}	
}

function FillDays(obj,mm,dd){
	if (obj){
		if(obj.options.length>0){
			while(obj.options.length>0){
				obj.options[0]=null;
			}
		}
		
		for(var i=0;i<mDays[mm];i++){
			obj.options[i] = new Option(right("00" + (i+1),2),right("00" + (i+1),2));
		}
		
		if(dd==null){obj.selectedIndex=0;}
		else if(dd>mDays[mm]){obj.selectedIndex = mDays[mm]-1;}
		else{obj.selectedIndex = dd-1;}
	}
}

function right(val, len){
	var out="";
	if(val.length<=len){return val;} //requested len too long
	for(var j=val.length; j>=(val.length - len); j--){out = val.charAt(j) + out;}
	return out;
}