function setDay(obj){
	obj = obj.form;
	var years = parseInt(obj.years.options[obj.years.selectedIndex].value);
	var months = parseInt(obj.months.options[obj.months.selectedIndex].value);
	var lastday = monthday(years,months);
	var itemnum = obj.days.length;
	if (lastday - 1 < obj.days.selectedIndex) {
		obj.days.selectedIndex = lastday - 1;
	}
	obj.days.length = lastday;
	for (cnt = itemnum + 1;cnt <= lastday;cnt++) {
		obj.days.options[cnt - 1].text = cnt;
	}
}
function monthday(years,months){
	var lastday = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
	if (((years % 4 == 0) && (years % 100 != 0)) || (years % 400 == 0)){
		lastday[1] = 29;
	}
	return lastday[months - 1];
}

function setDay1(obj){
	obj = obj.form;
	var years = parseInt(obj.years1.options[obj.years1.selectedIndex].value);
	if(years == "") {
		obj.months1.length = 1;
		obj.months1.selectedIndex = 0;
		obj.months1.options[0].text = "";
		obj.days1.length = 1;
		obj.days1.selectedIndex = 0;
		obj.days1.options[0].text = "";
	} else {
		obj.months1.length = 13;
		obj.months1.options[0].text = "";
		for (cnt = 1;cnt <= 12;cnt++) {
			obj.months1.options[cnt].text = cnt;
		}

		var months = parseInt(obj.months1.options[obj.months1.selectedIndex].text);
		if(months != "") {
			var lastday = monthday(years,months);
			var itemnum = obj.days1.length;
			if (lastday - 1 < obj.days1.selectedIndex) {
				obj.days1.selectedIndex = lastday - 1;
			}
			obj.days1.length = lastday+1;
			obj.days1.options[0].text = "";
			for (cnt = 1;cnt <= lastday;cnt++) {
				obj.days1.options[cnt].text = cnt;
			}
		} else {
			obj.days1.length = 1;
			obj.days1.selectedIndex = 0;
			obj.days1.options[0].text = "";
		}
	}
}

function setDay2(obj){
	obj = obj.form;
	var years = parseInt(obj.years2.options[obj.years2.selectedIndex].value);
	if(years == "") {
		obj.months2.length = 1;
		obj.months2.selectedIndex = 0;
		obj.months2.options[0].text = "";
		obj.days2.length = 1;
		obj.days2.selectedIndex = 0;
		obj.days2.options[0].text = "";
	} else {
		obj.months2.length = 13;
		obj.months2.options[0].text = "";
		for (cnt = 1;cnt <= 12;cnt++) {
			obj.months2.options[cnt].text = cnt;
		}

		var months = parseInt(obj.months2.options[obj.months2.selectedIndex].text);
		if(months != "") {
			var lastday = monthday(years,months);
			var itemnum = obj.days2.length;
			if (lastday - 1 < obj.days2.selectedIndex) {
				obj.days2.selectedIndex = lastday - 1;
			}
			obj.days2.length = lastday+1;
			obj.days2.options[0].text = "";
			for (cnt = 1;cnt <= lastday;cnt++) {
				obj.days2.options[cnt].text = cnt;
			}
		} else {
			obj.days2.length = 1;
			obj.days2.selectedIndex = 0;
			obj.days2.options[0].text = "";
		}
	}
}