帮忙解决一下frameset的问题（有源码）

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>Untitled Page</title>
     <script language="javascript" type="text/javascript">
        function SetUrl()
        {
           alert(window.frames["leftFrame"].location.href);
        }
    </script>
</head>
</head>
<body onload="SetUrl();">
  <frameset cols="180,*" frameborder="no" border="1" framespacing="0">
    <frame src="" name="leftFrame" id="leftFrame" title="leftFrame" scrolling="no"/>
    <frame src="" name="mainFram" id="mainFram" title="mainFram" scrolling="no" />
   </frameset>
  </body>
</html>

为什么提示为空或不是对象？ --------------------编程问答-------------------- alert(window.frames["leftFrame"].location.href)中的window.frames["leftFrame"].location.href是框架定位到某个页面，你没有给它值肯定会提示为空或不是对像，把整个改成：
window.frames["leftFrame"].location.href="1.html" --------------------编程问答--------------------

<html xmlns="http://www.w3.org/1999/xhtml" >

<head>

  <title>Untitled Page</title>

  <script language="javascript" type="text/javascript">  

  function SetUrl() 

  { 

  alert(window.frames["leftFrame"].location.href);  

  }

  window.onload = SetUrl

  </script>

</head>



 

  <frameset cols="180,*" frameborder="no" border="1" framespacing="0">

  <frame src="" name="leftFrame" id="leftFrame" title="leftFrame" scrolling="no"/>  

  <frame src="" name="mainFram" id="mainFram" title="mainFram" scrolling="no" />

  </frameset>



</html>

把body拿掉 --------------------编程问答-------------------- body去掉了，怎么还是js错误 --------------------编程问答-------------------- <frame src="<%Response.Write(URL_Menu); %>"....

    /// <summary>
    /// 定义公共变量
    /// </summary>
    public string apilist1 = "";
    public string URL = "";
    public string URL_Menu = "";
    override protected void OnInit(EventArgs e)
    {
        CheckAdminAuthority();
        if (CheckAuthorityCode("G1000"))
        {
           URL_Menu = "menu.aspx?type=0";
        } --------------------编程问答--------------------

引用楼主 zhangchuanliang 的回复:

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
  <title>Untitled Page</title>
  <script language="javascript" type="text/javascript">
  function SetUrl()
  {
  alert(window.frames["left……

当然为空了 LZ
你的alert本意是想得到src的内容而你的src是""的 --------------------编程问答-------------------- window.frames["leftFrame"].location.href

补充：.NET技术 ,  ASP.NET