之前老师领着做了一个项目，我是直接把那个项目的代码复制过来的，但是之前的树能正常显示，我的却不能，代码如下：
<%@ page pageEncoding="UTF-8"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title></title>
<link href="css/navbar.css" rel="stylesheet" type="text/css" />
<script language="JavaScript" type="text/javascript"
src="css/navbar.js"></script>
<style type="text/css">
body {
margin: 0px;
padding: 0px;
font-size: 12px;
}
</style>
<script language="javascript">
var show = true;
var open = null;
var hide = false;
//修改菜单的上下箭头符号
function my_on(head,body){ var tag_a;
for(var i=0;i<head.childNodes.length;i++){
if (head.childNodes[i].nodeName=="A"){
tag_a=head.childNodes[i];
break;
}
}
tag_a.className="on";
}
function my_off(head,body){
var tag_a;
for(var i=0;i<head.childNodes.length;i++){
if (head.childNodes[i].nodeName=="A"){
tag_a=head.childNodes[i];
break;
}
}
tag_a.className="off";
}
window.onload=function(){
var m1 =new Menu("menu1",'menu1_child','dtu','50',hide,my_on,my_off);
m1.init();
var m2 =new Menu("menu2",'menu2_child','dtu','50',hide,my_on,my_off);
m2.init();
var m3 =new Menu("menu3",'menu3_child','dtu','50',hide,my_on,my_off);
m3.init();
var m4 =new Menu("menu4",'menu4_child','dtu','50',hide,my_on,my_off);
m4.init();
var m5 =new Menu("menu5",'menu5_child','dtu','50',hide,my_on,my_off);
m5.init();
var m6 =new Menu("menu6",'menu6_child','dtu','50',hide,my_on,my_off);
m6.init();
};
</script>
</head>
<body>
<div id="menu">
<div class="tit" id="menu1">
<a href="javascript:void(0)" target="rightFrame" class="on"
id="menu1_a">员工管理</a>
</div>
<div class="list" id="menu1_child">
<ul>
<li>
<a target="rightFrame" href="${ctx}/emp/list.action">员工查询</a>
</li>
<li>
<a target="rightFrame" href="${ctx}/emp/getMessage.action">新进员工</a>
</li>
<li>
<a target="rightFrame"
href="${ctx}/emp/currDetail.action?emp.id=${sessionScope.curr_emp.id}">个人信息</a>
</li>
<li>
<a target="rightFrame" href="${ctx}/emp/logList.action">登陆日志</a>
</li>
</ul>
</div>
<div class="tit" id="menu2">
<a href="javascript:void(0)" target="rightFrame" class="on"
id="menu1_a">客户管理</a>
</div>
<div class="list" id="menu2_child">
<ul>
<li>
<a target="rightFrame" href="${ctx}/guest/list.action">我的客户</a>
</li>
<li>
<a target="rightFrame" href="${ctx}/guest/addguest.jsp">添加客户</a>
</li>
</ul>
</div>
<div class="tit" id="menu3">
<a href="javascript:void(0);" target="rightFrame" class="on"
id="menu1_a">客户往来记录</a>
</div>
<div class="list" id="menu3_child">
<ul>
<li>
<a target="rightFrame" href="${ctx}/plan/allList.action">所有工作计划</a>
</li>
<li>
<a target="rightFrame" href="${ctx}/plan/myList.action">我的工作计划</a>
</li>
<li>
<a target="rightFrame" href="${ctx}/record/allList.action">所有联系记录</a>
</li>
<li>
<a target="rightFrame" href="${ctx}/record/myList.action">我的联系记录</a>
</li>
</ul>
</div>
<div class="tit" id="menu4">
<a href="javascript:void(0)" target="rightFrame" class="on"
id="menu1_a">文档上传下载</a>
</div>
<div class="list" id="menu4_child">
<ul>
<li>
<a href="${ctx}/upload/upload.jsp" target="rightFrame">文档上传</a>
</li>
<li>
<a href="${ctx}/ud/List.action" target="rightFrame">文档下载</a>
</li>
</ul>
</div>
<div class="tit" id="menu5">
<a href="javascript:void(0)" target="rightFrame" class="on"
id="menu1_a">字典管理</a>
</div>
<div class="list" id="menu5_child">
<ul>
<li>
<a href="${ctx}/post/list.action" target="rightFrame">职务管理</a>
</li>
<li>
<a href="${ctx}/dept/list.action" target="rightFrame">部门设置</a>
</li>
<li>
<a href="${ctx}/col/list.action" target="rightFrame">系统菜单设置</a>
</li>
<li>
<a href="${ctx}/priv/list.action" target="rightFrame">功能设置</a>