如何用js做简单的页面切换过渡效果

*{margin:0;padding:0;}body{font-size:14px;font-family:"Microsoft YaHei";}ul,li{list-style:none;}#tab{position:relative;}#tab .tabList ul li{ float:left; background:#fefefe; background:-moz-linear-gradient(top, #fefefe, #ededed);