/*
 validates mail address, returns true / false and conditionally show alert window with message
*/
function validateMail(mail,errMessage)
{
	if (isValidMail(mail)){
		return true;
	} else {
		alert(errMessage);
		return false;
	}
}

function isValidMail(mail)
{
	var str=mail;
	var filter=new RegExp("^[_a-z0-9-]+([_a-z0-9-.])*@([_a-z0-9-]+[\.])+[_0-9a-z-]{2,4}$", "i");
	return filter.test(str);
}

/*
 validates mail item on onBlur event, display message, and conditionally return focus to that item.
*/

function validateMailOnBlur(mailItem,errMessage,focusBack,validEmpty)
{

	var str=mailItem.value;
	if (validEmpty) if (!str) return;
	var filter=new RegExp("^[_a-z0-9-]+[_a-z0-9-.]*@([a-z0-9-]+[\.])+[0-9a-z-]{2,}$", "i");
	if (filter.test(str)){
		return;
	} else {
		if (focusBack)
		{
		alert(errMessage);
		mailItem.focus();
		} else
		{
		alert(errMessage);
		}
	}
}