if($("#auto_list").size()>0){
	var list_key;
	function auto_display(){
	list_key = setInterval(function(){
		var li_width = $("#auto_list>li").width()+parseInt($("#auto_list>li").css("marginRight").replace("px",""));
		var p_num = $("#auto_list>li").size();//标示当前共有多少个产品介绍
		$("#auto_list:not(:animated)").find("li").eq(0).clone().appendTo("#auto_list");
		var margin_left = parseInt($("#auto_list").css("margin-left").replace("px",""))-li_width;
		$("#auto_list:not(:animated)").stop().animate({"margin-left":margin_left+"px"},500,function(){
			$("#auto_list li").eq(0).remove();														 
			$("#auto_list").css("margin-left","0");
		});	
	},3000);
	}
	auto_display();
}
$("#last").click(function(){
		clearInterval(list_key);
		var li_width = $("#auto_list>li").width()+parseInt($("#auto_list>li").css("marginRight").replace("px",""));
		var p_num = $("#auto_list>li").size();//标示当前共有多少个产品介绍
		$("#auto_list:not(:animated)").find("li").eq(0).clone().appendTo("#auto_list");
		var margin_left = parseInt($("#auto_list").css("margin-left").replace("px",""))-li_width;
		$("#auto_list:not(:animated)").stop().animate({"margin-left":margin_left+"px"},500,function(){
			$("#auto_list li").eq(0).remove();														 
			$("#auto_list").css("margin-left","0");
			auto_display();
		});	
		
	});
	
	$("#next").click(function(){
		clearInterval(list_key);
		var p_num = $("#auto_list>li").size();//标示当前共有多少个产品介绍
		var li_width = $("#auto_list>li").width()+parseInt($("#auto_list>li").css("marginRight").replace("px",""));
		margin_left = parseInt($("#auto_list").css("margin-left").replace("px",""))-li_width;
		$("#auto_list:not(:animated)").find("li").eq(p_num-1).clone().prependTo("#auto_list");//先将最后一张复制到第一张去
		$("#auto_list").css("margin-left",margin_left+"px");
		margin_left = margin_left+li_width;
		$("#auto_list:not(:animated)").stop().animate({"margin-left":margin_left+"px"},500,function(){
			$("#auto_list li").eq(p_num).remove();
			auto_display();
		});
	});