$(document).ready(function(e) {
		
   	    var lis=$("#bannerb ul li");
		var len=lis.length;
		var index = 0;
		var pictimer;
		var scrolltime=3500; //图片切换时间
		
		pictimer=setinterval(scrollfun,scrolltime); //加载后自动播放

		//鼠标上浮后停止滚动并显示左右箭头，离开后自动播放
		$("#bannerb").on({
			"mouseover":function(){
				clearinterval(pictimer);
				$("#bannerb .bannebtl").css("display","block");
				$("#bannerb .bannebtr").css("display","block");
			},
			"mouseleave":function() {
				pictimer = setinterval(scrollfun,scrolltime); 
				$("#bannerb .bannebtl").css("display","none");
				$("#bannerb .bannebtr").css("display","none");
			},
			"contextmenu":function(){
				return false;
			}
		});
		
		
		//滚动函数
		function scrollfun(){
			index++;
			if(index == len) {index = 0;}
			showpics(index);		//图片滚动与语句顺序有关！	
		}
		
		//以下代码添加数字按钮，还有上一页、下一页两个按钮
		if(len>1){
			var btn="<div id='bannebt' class='bannebtl'></div><div id='bannebt' class='bannebtr'></div>"
			btn += "<div id='banneindex'>";

			for(var i=0;i<len;i++) {
				btn += "<span></span>";
			}
			btn += "</div>";
			
			$("#bannerb").append(btn);
			
			$("#bannerb #banneindex span").first().css("background","red"); //加载时第一张问为选中状态
			
			//数字按钮鼠标划上动作
			$("#bannerb #banneindex span").mouseover(function(){
				showpics($(this).index());
			});
			
			//切换到前一张
			$("#bannerb .bannebtl").click(function(){
				index--;
				if(index == -1) {index = len - 1;}
				showpics(index);
			});
			
			//切换到后一张
			$("#bannerb .bannebtr").click(function(){
				index++;
				if(index == len) {index = 0;}
				showpics(index);
			});
			
		}
		
		//图片切换函数
		function showpics(index){ 
			$("#bannerb ul li:eq("+index+")").stop(true,true).show();
			$("#bannerb ul li:gt("+index+")").stop(true,true).hide();
			$("#bannerb ul li:lt("+index+")").stop(true,true).hide();	
			if(len>1){
				$("#bannerb span:eq("+index+")").css("background","red");
				$("#bannerb span:gt("+index+")").css("background","#999");
				$("#bannerb span:lt("+index+")").css("background","#999");
			}	
		}
});