jQuery.isEmail = function(email) {
	if ((email == undefined) || (email) == "") return false;

	var email = new String(email);

	var splitted = email.match("^(.+)@(.+)$");
	if (splitted == null) return false;
	if (splitted[1] != null ) {
		var regexp_user = /^\"?[\w-_\.]*\"?$/;
		if (splitted[1].match(regexp_user) == null) return false;
	}
	if (splitted[2] != null) {
		var regexp_domain = /^[\w-\.]{2,}\.[A-Za-z]{2,4}$/;
		if (splitted[2].match(regexp_domain) == null) {
			var regexp_ip = /^\[\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\]$/;
			if (splitted[2].match(regexp_ip) == null) return false;
		}
		return true;
	}
	return false;
}