<!DOCTYPE html> <html lang="zh-cn"> <head> <meta charset="UTF-8"> <title>随机显示广告图片</title> </head> <body> <script> advertisement = new Array(4); advertisement[0] = ‘<img src="http://www.lanrentuku.com/down/js/images/12498863530.jpg" />‘; advertisement[1] = ‘<img src="http://www.lanrentuku.com/down/js/images/12498863531.jpg" />‘; advertisement[2] = ‘<img src="http://www.lanrentuku.com/down/js/images/12498863532.jpg" />‘; advertisement[3] = ‘<img src="http://www.lanrentuku.com/down/js/images/12498863533.jpg" />‘; var index = Math.floor(Math.random() * advertisement.length); document.write(advertisement[index]); </script> <p>刷新下看看效果吧~</p> </body> </html>
原文：http://www.cnblogs.com/lqcdsns/p/5937787.html