<!-- Begin

//check if an input value has been entered
function isEmpty(inputStr)	
{
	if (inputStr == null || inputStr == "")
		return true
	else 
		return false
}

//check if a drop down item has been selected
function notSelected(select)	
{
	if (select == 0)
		return true
	else 
		return false
}

//check if a radio button from a group has been selected, only work for two-radio-button group
function radioNotChecked(radio)
{
	if (!((radio[0].checked) || (radio[1].checked )))	 
		return true	//not checked
	else
		return false	//checked
}

//check if a check box has been checked
function notChecked(Checkbox)
{
	if (!Checkbox.checked)	 
		return true	//not checked
	else
		return false	//checked
}

//check if the format of email address is correct
function isEmailAddrValid(email)
{
	// define regex
	var pattern = /^[0-9a-zA-Z]([-_.]?[0-9a-zA-Z])*@[0-9a-zA-Z]([-.]?[0-9a-zA-Z])*\.[a-zA-Z]{2,3}$/;

	// test for pattern
	if(pattern.test(email))
		return true;
	else
		return false;
}

//check if the format of date is correct
function isDateValid(date)
{
	// define regex
	var pattern = /^[0-9]{4}-[0-9]{2}-[0-9]{2}$/;

	// test for pattern
	if(pattern.test(date))
		return true;
	else
		return false;
}
// End -->