<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<style type="text/css">
img
{
width:200px; height:200px;
}
</style>
<script src="jquery-1.9.1.js" type="text/javascript"></script>
<script type="text/javascript">
$(function () {
$('#btn1').click(function () {
var num = Math.floor(Math.random() * 8 + 1);
$('img').attr('src','picture/'+num+'.jpg')
})
})
</script>
</head>
<body>
<img src="picture/1.jpg" id="img1" />
<input id="btn1" type="button" value="变换" />
</body>
</html>