window.addEvent('domready', function(){ 
    var menu = $$('#menu a');
    menu.each(function(element) { 
          var fx = new Fx.Styles(element, {duration:400, wait:false});
          element.addEvent('mouseenter', function(){
               fx.start({'opacity': 0.01});
          });
          element.addEvent('mouseleave', function(){
               fx.start({'opacity': 1});
          });
     });
});