要完成此效果把如下代码加入到中区域中 <script LANGUAGE="JavaScript"> bg = new Array(2); bg[0] = 'http://www.jojoo.net/logo.gif' bg[1] = '.gif' bg[2] = 'http://www.jojoo.net/include/1jpg' index = Math.floor(Math.random() * bg.length); document.write(""); </script>