function populate(objForm,selectIndex) {
timeA = new Date(objForm.year.options[objForm.year.selectedIndex].text, objForm.month.options[objForm.month.selectedIndex].value,1);
timeDifference = timeA - 86400000;
timeB = new Date(timeDifference);
var daysInMonth = timeB.getDate();
for (var i = 0; i < objForm.day.length; i++) {
objForm.day.options[0] = null;
}
for (var i = 0; i < daysInMonth; i++) {
objForm.day.options[i] = new Option(i+1);
objForm.day.options[i].value = i+1;
}
document.Cartdetailform.day.options[0].selected = true;
}

function getYears() {

// You can easily customize what years can be used
var years = new Array(1997,1998,1999,2000,2001,2005)

for (var i = 0; i < document.Cartdetailform.year.length; i++) {
document.Cartdetailform.year.options[0] = null;
}
timeC = new Date();
currYear = timeC.getFullYear();
for (var i = 0; i < years.length; i++) {
document.Cartdetailform.year.options[i] = new Option(years[i]);
}
document.Cartdetailform.year.options[2].selected=true;
}

function IsBlank(field, fieldname)
{
	if (field == "" || field == null ){
		alert("Please input " + fieldname);
		return true;
	}
	return false;
}

function IsValidEmail(email) {
if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(email.value)){
return (true)
}
alert("Invalid E-mail Address! Please re-enter.")
return (false)
}

function IsNumber(field) {
var valid = "0123456789"
var ok = "yes";
var temp;
for (var i=0; i<field.length; i++) {
temp = "" + field.substring(i, i+1);
}
if (valid.indexOf(temp) == "-1") 
   return false;
return true;
}

function IsPhoneNumber(field){
	if ((field.value.length>7) && IsNumber(field.value))
	{
		alert("Please input a valid phone number!");
		return false;
	}
	return true;
}

function IsValidDate(dateStr) {
// Checks for the following valid date formats:
// MM/DD/YY   MM/DD/YYYY   MM-DD-YY   MM-DD-YYYY
// Also separates date into month, day, and year variables

//var datePat = /^(\d{1,2})(\/|-)(\d{1,2})\2(\d{2}|\d{4})$/;

// To require a 4 digit year entry, use this line instead:
var datePat = /^(\d{1,4})(\/|-)(\d{1,2})\2(\d{2})$/;

var matchArray = dateStr.match(datePat); // is the format ok?
if (matchArray == null) {
alert("Date is not in a valid format.")
return false;
}
year = matchArray[1]; // parse date into variables
month = matchArray[3];
day = matchArray[4];

if (year.length < 4) { // check month range
alert("Year must be 4 digits.");
return false;
}

if (month < 1 || month > 12) { // check month range
alert("Month must be between 1 and 12.");
return false;
}
if (day < 1 || day > 31) {
alert("Day must be between 1 and 31.");
return false;
}
if ((month==4 || month==6 || month==9 || month==11) && day==31) {
alert("Month "+month+" doesn't have 31 days!")
return false
}
if (month == 2) { // check for february 29th
var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
if (day>29 || (day==29 && !isleap)) {
alert("February " + year + " doesn't have " + day + " days!");
return false;
   }
}
return true;  // date is valid
}