HTML代码：
<! DOCTYPE html>
<head>
<title></title>
<meat charset="utf-8">
</head>
<body>
<div class="toggle">
<img src="images/">
<img src="images/">
<img src="images/">
</div>
</body>
</html>
CSS样式表代码：
div.toggle img{width:200px;height:180px; float:right};
body{background-image:url()};
javascript代码：
var toggle=document.getElementsByTagName("img");
var body=document.getElementsByTagName("body") ;
toggle.onclick=function(){
body[0].style.backgroundImage="url(this.getAttribute(url))";
}
原文：http://www.cnblogs.com/zhangyang0619/p/5839654.html