JQuery product intermittent scroll down effect core code

 
$(function(){ 
var _BuyList=$("#buyList"); 
var Trundle = function () { 
_BuyList.prepend(_BuyList.find("li:last")).css('marginTop', '-85px'); 
_BuyList.animate({ 'marginTop': '0px' }, 800); 
} 
var setTrundle = setInterval(Trundle, 3000); 
_BuyList.hover(function () { 
clearInterval(setTrundle); 
setTrundle = null; 
},function () { 
setTrundle = setInterval(Trundle, 3000); 
}); 
});