每隔一定时间跟换图片
Img = new Array("image/2.jpg","image/1.jpg","image/3.jpg","image/4.jpg");
size = Img.length;
i = 0;
function chImg(){
picID.src = Img[i];
i++;
if (i>=size) i = 0;
setTimeout("chImg()",1000);
} <body onLoad="chImg()">
<img id="picID">
</body>