// return true if valid email other false
function valid_email(email_address) {
	var emailRegEx = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	
	if (email_address.match(emailRegEx)) {
		return true;
	} else {
		return false;
	}
}