var changeTime=5000;//切换时间
 document.write("");
 var obj=$("li img")[0];
 //alert('2');
 var timer;
 function change(){
	//如果已经处于active状态，return
	if ($(obj).attr("class")=="active") return;
	//active状态的图片恢复原样
	$("li img.active").fadeTo(200,0.6)
	.removeClass("active")
	.animate({top:4,width:116,height:25,left:0},300)
	.parent().css({"color":"#fff"});
	//获取数据
	
	var x = $(obj).attr("pic");
	//当前
	$(obj).animate({top:0,width:118,height:27,left:0},100)
	.addClass("active")
	.fadeTo(200,1)
	.parent().css({"color":"#888"});
	$("#back").children().addClass("gray").end()
		.fadeTo(500,0.1,function(){
			$(this).children("img").attr("src","images/banner/"+x+".jpg").removeClass("gray");	  //更改图片
			$(this).fadeTo(500,1);
	});
	var nextImg=$(obj).parent().next().children("img");
	if(nextImg.attr("src")==$.undefined){
		obj=$("li img")[0];
	}else{
		obj=nextImg;
	}
 }
 
 //自动切换
 function show(){
		change();
		timer=setTimeout(show,changeTime);
 }
show();
 //手工切换
$("li img").click(function(){
	clearTimeout(timer);//重新记时
	obj=$(this);
	change();
	timer=setTimeout(show,changeTime);
});