function updateDays(monthCtrl,dayCtrl,yearCtrl){
	var curDay	= dayCtrl.selectedIndex;
	var dd = new Date(yearCtrl[yearCtrl.selectedIndex].value, monthCtrl[monthCtrl.selectedIndex].value, 0);
	days	= dd.getDate();
	dayCtrl.options.length	= 0;
	var prefix	= "0";
	for(var i=1;i<=days;i++){
		if(i<10) prefix = "0"; else prefix = "";
		dayCtrl.options[dayCtrl.options.length]	= new Option(prefix+i,i);
	}
	if(dayCtrl.options.length>curDay) dayCtrl[curDay].selected = "selected"; else dayCtrl[dayCtrl.options.length-1].selected = "selected";
	return true;
}