function emailValidation() {
var emailRegEx =/^([a-zA-Z0-9])(([a-zA-Z0-9])*([\._-])?([a-zA-Z0-9]))*@(([a-zA-Z0-9\-])+(\.))+([a-zA-Z]{2,4})+$/

if (document.newsletter.email.value.search(emailRegEx )==-1) //if match failed
	{
	alert("Please enter a valid email address.");
	return false;
	}
	else
	{
	return true;
	}
}