js 下拉菜单实现代码

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> <title> </title> <meta name="description" content=" "> <meta name="keywords" content=" "> <meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" /> <style type="text/css"> *{padding:0;margin:0;} .nav{width:850px;margin:50px auto;position:relative;} .nav li{display:inline;margin-right:50px;} .nav ol{background-color:#f5f5f5;border:1px solid #ccc;display:none;padding:15px;} .nav ol li{display:block;margin-bottom:15px;} </style> <script type="text/javascript"> var next=function (el) { do { el = el.nextSibling; } while ( el && el.nodeType != 1 ); return el; } var showContent=function (el) { var _next=next(el); _next.style.display="block"; _next.style.position="absolute"; _next.style.zIndex="999"; _next.style.top=el.offsetHeight+el.offsetTop+"px"; _next.style.left=el.offsetLeft+"px"; _next.onmouseout=function (){ this.style.display="none"; } _next.onmouseover=_next.onmousemove=function (){ this.style.display="block"; } } var hideContent=function (el) { el.style.display="none"; } </script> </head> <body> <!--页眉开始--> <ul> <li> 首页 <ol> <li>首页1</li> <li>首页2</li> <li>首页3</li> <li>首页4</li> <li>首页4</li> </ol> </li> <li> 电影 <ol> <li>电影1</li> <li>电影2</li> <li>电影3</li> <li>电影4</li> <li>电影4</li> </ol> </li> <li>新闻</li> <li>新片</li> <li>排行榜</li> </ul> dcxsssssssss <!--页眉结束--> </body> </html>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]