First, hierarchical navigation
<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
Second, hidden navigation
<title> Hide Navigation </title><style type= "Text/css" >*{font-size:24px;text-align:center;line-height:50px ;}. A{color: #F00, border:0px solid #000 width:150px;height:50px;background-color: #FF0;p osition:fixed;left:30px;top : 30px;overflow:hidden;}. Aa{color: #F00, border:0px solid #000 width:150px;height:50px;background-color: #93F;p osition:fixed;left:30px;top : 30px;overflow:visible;}. B{width:150px;height:50px;top:50px;left:0px;overflow:hidden;}. bb{width:150px;height:50px;top:50px;left:0px;overflow:visible;}. c{width:450;height:200;position:relative;left:150px;top:-50px;} table{border= "0"; width:450px;height:200px;} </style>
Hierarchical navigation and hidden navigation