window.addEvent('domready', function() {
 
  $$('.dropdown li').each(function(el) {


    var reset = false;
    var fx = new Fx.Tween(el,{
      duration: 200,
      link: 'cancel',
      onComplete:function() {
        if(reset) {
          el.setStyle('background-position','0 0');
        }
      }
    });


    el.setStyle('background-position','0 0').addEvents({
      'mouseenter': function(e) {
        e.stop();
        fx.start('background-position','0 20px');
        reset = false;
      },
      'mouseleave': function(e) {
        reset = true;
        fx.start('background-position','0 40px');
      }
    });
  });
  




});