在网页中经常会需要这种图片轮换效果，记录在此，方便以后使用咯！
效果一：
[img]http://dl.iteye.com/upload/picture/pic/54520/c3d96d80-5318-3224-a197-f88d2ba6e48f.jpg[/img]
效果二：
[img]http://dl.iteye.com/upload/picture/pic/54522/d39524cf-0206-38e1-961e-d8f5aae6183b.jpg[/img]