function valid_ml(ml) {
  var lusr = "([a-zA-Z0-9][a-zA-Z0-9_.-]*|\"([^\\\\\x80-\xff\015\012\"]|\\\\[^\x80-\xff])+\")";
  var ldom = "([a-zA-Z0-9][a-zA-Z0-9._-]*\\.)*[a-zA-Z0-9][a-zA-Z0-9._-]*\\.[a-zA-Z]{2,5}";
  var lregex = "^" + lusr + "\@" + ldom + "$";

  var rgx    = new RegExp(lregex);
  return rgx.exec(ml) ? true : false;
}