function animateFlashMessage(){
      // do the flash disappear (duration 6.0 sec)
      var f = $('flashMessage');
      if (f && f.style.display != 'hidden') {
          new Effect.Parallel([
                new Effect.Fade(f, {sync: true})
                ], { duration: 6.0
                });
      }
  }
  Event.observe(window, 'load', function () {
      animateFlashMessage();
  });