JavaEE框架 树状结构菜单的跳转(),该如何处理

JavaEE框架 树状结构菜单的跳转(<sx:tree>)
Java code
<%@page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="javax.swing.JFrame" %>
<%@taglib prefix="s" uri="/struts-tags"%>
<%@taglib prefix="sx" uri="/struts-dojo-tags"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
    <head>
        <base href="<%=basePath%>">

        <title>操作列表</title>

        <meta http-equiv="pragma" content="no-cache">
        <meta http-equiv="cache-control" content="no-cache">
        <meta http-equiv="expires" content="0">
        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
        <meta http-equiv="description" content="This is my page">
        <sx:head parseContent="true"/> 
        <link rel="stylesheet" type="text/css" href="css/common.css">
        <script type="text/javascript" language="javascript" charset="utf-8">
         dojo.event.topic.subscribe("treeSelected",function treeNodeSelected(source){
           dojo.io.bind({
            url: "admin/student/"+source.widgetId+".jsp",
            load: function(type, data, evt) {
                  var src = evt.target;
                  alert(src.nodeName);
            },
            mimeType: "text/html"
        });
        });
        </script>
    </head>

    <body style="background: url(images/bg.png)">
        <sx:tree label="管理系统" id="root" rootNode="管理系统 "  treeSelectedTopic="treeSelected">
            <sx:treenode label="考生信息管理">
                <sx:treenode label="添加考生" id="addStu"/>
                <sx:treenode label="考生信息修改" id="modStu"/>
            </sx:treenode>
            <sx:treenode label="题库管理">
                <sx:treenode label="添加试题"/>
                <sx:treenode label="删除试题" />
                <sx:treenode label="修改试题" />
            </sx:treenode>
            <sx:treenode label="试卷管理">
                <sx:treenode label="删除试卷" />
                <sx:treenode label="生成试卷" />
            </sx:treenode>
            <sx:treenode label="考试安排">
                <sx:treenode label="" />
                <sx:treenode label="" />
            </sx:treenode>
            <sx:treenode label="成绩查询">
                <sx:treenode label="" />
                <sx:treenode label="" />
            </sx:treenode>
        </sx:tree>
    </body>
    <script type="text/javascript">
       window.onload=function(){ 
       var nodes =dojo.widget.manager.getWidgetsByType('struts:StrutsTreeNode'); 
       for( var i=0; i < nodes.length; i++){ 
              nodes[i].expand(); 
          } 
       }
    </script>
</html>


上面是struts框架的一个树状菜单,问题是我想点击的时候它在一个指定的<iframe>中显示我想要的页面,现在不知道怎么办?dojo是必须用的吗?以前的javascript咋都不行了,求解决!主要是讲讲为什么用dojo,不用不行吗?
Java code

<html>
    <head>
        <base href="<%=basePath%>">

        <title>管理员主界面</title>

        <meta http-equiv="pragma" content="no-cache">
        <meta http-equiv="cache-control" content="no-cache">
        <meta http-equiv="expires" content="0">
        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
        <meta http-equiv="description" content="This is my page">
        <link rel="stylesheet" type="text/css" href="css/main_admin.css" />
        <script language="javascript" src="js/common.js" charset="utf-8"></script>
    </head>

    <body>
        <div id="wrap">
            <div id="head" style="background-color: purple; margin-top: -15px;">
                <div id="head1">
                    <span style="font-weight: bold; font-size: 35px;"> 在线考试系统 </span>
                    <span id="navigation" style="margin-left: 800px;"> <a
                        href="javascript:void(0)" onclick="loginOut('Admin')">退出系统</a> <a href="#">使用帮助</a> <a href="#">返回首页</a> </span>
                </div>
                <div id="head2" style="margin-top: 25px;">
                    <span style="clear: both; margin-left: 1050px;">今天是:<script>getCurrentTime()</script> </span>
                </div>
                <div id="head3" style="background-color: gray;">
                    您好:
                </div>
            </div>
            <div id="content">
                <table width="100%" height="100%">
                    <tr>
                        <td width="20%" height="100%">
                            <iframe src="admin/leftList.jsp" scrolling="no" frameborder="0"
                                id="leftList" height="100%" width="100%"></iframe>
                        </td>
                        <td style="background-color: gray;">
                        </td>
                        <td width="79%" height="100%">
            <!--在此iframe中显示-->
                            <iframe src="admin/welcome.jsp" scrolling="auto" frameborder="0"
                                width="100%" height="100%" id="main" name="main"></iframe>
                        </td>
                    </tr>
                </table>
            </div>
            <div id="footer">
                <jsp:include page="/commons/footer.jsp"></jsp:include>
            </div>
        </div>
    </body>
</html>