JavaScript 实现每日自动更换图片的方法

<!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>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>无标题文档</title>
</head>
<body>
 <a target="_blank" id="a"><img id="img" /></a>
 <script type="text/javascript">
 var imgSrc = new Date().getDate() +'.jpg';
 document.getElementById('img').src = imgSrc;
 document.getElementById('a').href = imgSrc ;
 </script>
</body>
</html>