<!DOCTYPE html>
<html>
<head>
<title>baidu</title>
<meta charset="utf-8">
<style type="text/css">
.box{
position: relative;
left: 500px;
}
body{
background-image: url(1.jpg);
}
</style>
</head>
<body>
<div class="box">
<img src="1.jpg" alt="" width="150" id="pic1"/>
<img src="2.jpg" alt="" width="150" id="pic2"/>
<img src="3.jpg" alt="" width="150" id="pic3"/>
</div>
<script type="text/javascript">
var pic1 = document.getElementById("pic1");
var pic2 = document.getElementById("pic2");
var pic3 = document.getElementById("pic3");
pic1.onclick = function(){
document.body.style.backgroundImage = "url(1.jpg)";
}
pic2.onclick = function(){
document.body.style.backgroundImage = "url(2.jpg)";
}
pic3.onclick = function(){
document.body.style.backgroundImage = "url(3.jpg)";
}
</script>
</body>
</html>