IE6中选项卡没有反应 为什么?
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default4.aspx.cs" Inherits="Default4" %>
<!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 id="Head1" runat="server">
     <title></title>
     <script type="text/javascript">
         function setTab(name, cursel, n) {
             for (i = 1; i <= n; i++) {
                 var menu = document.getElementById(name + i);
                 var con = document.getElementById("con_" + name + "_" + i);
                 menu.className = i == cursel ? "hover" : "";
                 con.style.display = i == cursel ? "block" : "none";
             }
         }
     </script>
     <style type="text/css">
         *
         {
             margin: 0px;
             padding: 0px;
             list-style: none;
         }
         .main
         {
             width: 700px;
             height: 600px;
             float: left;
             display: inline;
             padding: 3px;
             background-color: Gray;
         }
         .main .menu
         {
             width: 306px;
             height: 31px;
             overflow: hidden;
             float: left;
         }
         .main .menu span
         {
             width: 60px;
             height: 30px;
             line-height: 30px;
             overflow: hidden;
             text-align: center;
             float: left;
             margin: 1px 0 0 1px;
             background-color: Yellow;
             color: #BCBCBC;
             font-weight: bold;
             cursor: pointer;
             font-size: 12px;
         }
         .main .menu .hover
         {
             background: #666;
             color: #FFF;
         }
         .main .content
         {
             width: 700px;
             height: 500px;
             overflow: hidden;
             float: left;
             margin: 1px;
             margin-top: 0px;
             display: inline;
             background-color: White;
         }
         .main .content div
         {
             width: 700px;
             height: 500px;
             color: Red;
             font-weight: bold;
         }
     </style>
</head>
<body>
     <form id="form1" runat="server">
     <div class="main">
         <div class="menu">
             <span id="one1" onclick="setTab('one',1,2)" class="hover">选项卡1</span> <span id="one2"
                 onclick="setTab('one',2,2)">选项卡2</span>
         </div>
         <div class="content">
             <div id="con_one_1">
                 内容一
             </div>
             <div id="con_one_2" style="di