<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<div>
<img id="img" src="css/img/1.png"/>
</div>
<script type="text/javascript">
window.onload=function(){
img=document.getElementById("img");
setInterval("lunbo()",1000);
}
i=2;
function lunbo(){
img.src="css/img/"+i+".png";
i++;
if(i>4){
i=1;
}
}
</script>
</body>
</html>
原文：http://www.cnblogs.com/yangfan19890919/p/4716034.html