function checkMail(vEmail)
{
var x = vEmail;
var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(x)) 
	{
		return true;
	}
	else 
	{
		return false;
	}
}	

function Validate()
{	
	if(document.newsletterSubscriber.textfield.value=="")
	{
		alert("Please enter email address.");
		document.newsletterSubscriber.textfield.value="";
		document.newsletterSubscriber.textfield.focus();
		return false;
	}
	if(document.newsletterSubscriber.textfield.value!="" && !checkMail(document.newsletterSubscriber.textfield.value))
	{
		alert("Please enter valid email address.");
		document.newsletterSubscriber.textfield.focus();
		return false;
	}
	return true;
	//document.newsletterSubscriber.submit();
}