菜单自动展开（js实现）
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><html> <head> <title>Untitled </title> <script> window.onload = function() { var childs = document.getElementById("container").childNodes; for (var i = 0;i < childs.length;i++) { if (childs[i].tagName == "LI") { addEvent(childs[i]); } } } function addEvent(o) { var as = o.getElementsByTagName("a"); as[0].onclick = function(e){ var theEvent = window.event || e; var link = theEvent.srcElement ? theEvent.srcElement : theEvent.target; var uls = link.parentNode.childNodes; for (var i = 0;i < uls.length;i++) { if (uls[i].tagName == "UL") { if (uls[i].style.display == "none") { uls[i].style.display = ""; } else { uls[i].style.display = "none"; } } } } } </script> </head> <body> <ul id="container"> <li> <a href="#">Menu01</a> <ul> <li>A1</li> <li>A2</li> </ul> </li> <li> <a href="#">Menu02</a> <ul> <li>B1</li> <li>B2</li> </ul> </li> </ul> </body></html>