var ResHTML="";
var TimerID;
var i=0,j=0;
var SwapID="SwapPictureDivUl";   //Ul 的ID
var NavID="SwapPictureNavLi";
var NowPicLi=0;  //初始化显示第一条
var SwapLists=document.getElementById(SwapID);
var SwapList=SwapLists.getElementsByTagName("li");
var SwapNav=document.getElementById(NavID);
var NavList=document.getElementById(NavID).childNodes;


//定义的函数
function SwapPic(ShowNum){
i=0;  //变量
NowPicLi=ShowNum;

for(i;i<SwapList.length;i++){   //循环所有li
	if(i==NowPicLi){     //如何当前LI  == 要显示的 LI
		SwapList.item(i).style.display="";   //显示
		NavList.item(i).className="NavLiOn";
		}else{
		SwapList.item(i).style.display="none";  //隐藏
		NavList.item(i).className="NavLiOff";
		}
}

NowPicLi++;   //自动++
if(NowPicLi>=SwapList.length){NowPicLi=0;}  //如果超出 Li的数量则初始化
clearTimeout(TimerID);
TimerID=setTimeout("SwapPic("+NowPicLi+")",2700);  //每 1.600秒执行一次
//setTimeout("SwapPic("+NowPicLi+")",3000);  //每 1.600秒执行一次

}

for(i;i<SwapList.length;i++){
	j=i+1;
	ResHTML=ResHTML + "<li onclick='SwapPic("+i+")'>"+j+"</li>";
	}
SwapNav.innerHTML=ResHTML;
SwapPic(0);