$(function(){
   var num=0;
   var imgWidth=155;//图片的宽度
   var speed=20;//流动的速度，每20毫秒一个像素
   function howlking(){
   num++;
   if(num<imgWidth){
         $('.scroll ul').css('left',-num+"px");
   }else{
      $('.scroll ul').find('li:first').appendTo($('.scroll ul'));
   $('.scroll ul').css('left',"0px");
   num=0;
   }
   }
   var times=setInterval(howlking,speed);
   $('.scroll').hover(function(){clearTimeout(times)},function(){times=setInterval(howlking,speed)});
});