$(function(){

	function scollDown(id,time){
          var liHeight=$("#"+id+" ul li").height();
          var time=time||2500;
          setInterval(function(){
          $("#"+id+" ul").prepend($("#"+id+" ul li:last").css("height","0px").animate({
          	height:liHeight+"px"
          },"slow"));
          },time);
        

	}

	scollDown("pingjia",3000);
	scollDown("fahuo",3000);

});