var filter=/^.+@.+\..{2,3}$/

function addAddress() {
	var email = document.newsletter.email.value;
	if (filter.test(email)){
		location.href='/?action=d7_maillist_public_add_address&Address=' + email + '&Group_ID=14819';
	} else {
		alert("Please input a valid email address.");
	}	
}