function checkEmail(e, error_msg) {
	var email = document.getElementById(e);
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (!filter.test(email.value)) {
		alert(error_msg);
		email.select();
		return false;
	}
}