function checkDates(el) {
	if(document.getElementById && el.nextSibling) {
		var selectList=findNextSelect(el);
		if(el.selectedIndex == 1 ||	el.selectedIndex == 3 ||	el.selectedIndex == 5 ||	el.selectedIndex == 7 ||	el.selectedIndex == 8 ||	el.selectedIndex == 10 ||	el.selectedIndex == 12) {
			while(selectList.options.length>1) {
				selectList.options[selectList.options.length-1] = null;
			}
			for(var i=1;i<=31;i++) {
				var txt = (i<10) ? '0'+i : i;
				selectList.options[i] = new Option(txt);
			}
		} else if(el.selectedIndex == 4 ||	el.selectedIndex == 6 ||	el.selectedIndex == 9 ||	el.selectedIndex == 11) {
			while(selectList.options.length>1) {
				selectList.options[selectList.options.length-1] = null;
			}
			for(var i=1;i<=30;i++) {
				var txt = (i<10) ? '0'+i : i;
				selectList.options[i] = new Option(txt);
			}
		} else {
			while(selectList.options.length>1) {
				selectList.options[selectList.options.length-1] = null;
			}
			for(var i=1;i<=28;i++) {
				var txt = (i<10) ? '0'+i : i;
				selectList.options[i] = new Option(txt);
			}
		}
	}
}

function findNextSelect(el) {
	var selectList;
	if(el.nextSibling.nodeName=="SELECT") selectList=el.nextSibling;
	else selectList=findNextSelect(el.nextSibling);
	return selectList;
}