$(document).ready(function(){
 
    //Set opacity on each span to 0%
    $(".rollover").css({'opacity':'0'});
 
	$('ul a').hover(
		function() {
			$(this).find('.rollover').stop().fadeTo(200, 1);
		},
		function() {
			$(this).find('.rollover').stop().fadeTo(200, 0);
		}
	)
 
});