document.observe("dom:loaded", function() {
  $$("form.validated").each(function(f) {
    f.observe("submit", function(e) {
      var form = e.element();
      form.select("label.required").each(function(label) {
        var field = label.readAttribute("for");
        if ($(field).value == "") {
          alert(label.innerHTML + " must be filled in!");
          e.stop();
          throw $break;
        }
      });
      return false;
    });
  });
});