$(function() {  
// OPACITY OF BUTTON SET TO 50%  
$(".fader").css("opacity","1.0");  
 
// ON MOUSE OVER  
$(".fader").hover(function () {  

// SET OPACITY TO 100%  
$(this).stop().animate({  
opacity: 0.5  
}, "fast");  
},  
 
// ON MOUSE OUT  
function () {  
  
// SET OPACITY BACK TO 50%  
$(this).stop().animate({  
opacity: 1.0  
}, "slow");  
});  
});