*{ margin:0; padding:0; list-style:none}
.box{ width:300px; margin:50px auto; border:1px solid #ccc;}
.hd,.bd{ overflow:hidden}
.hd li{ float:left; height:30px; line-height:30px; background:#CCC; width:100px; text-align:center; cursor:pointer}
.hd li.on{ background:#FFF}
.bd li{ display:none;text-align:center; line-height:100px;}
.bd li.on{ display:block}