easyui选项卡的问题

<%@ Master Language="C#" AutoEventWireup="true" CodeFile="Master.master.cs" Debug="true" Inherits="Master" %><!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 runat="server">
    <title></title>
    <asp:ContentPlaceHolder id="head" runat="server">
    </asp:ContentPlaceHolder>
    <script src="../jquery-easyui-1.2.3/jquery-1.4.4.min.js" type="text/javascript"></script>
    <script src="../jquery-easyui-1.2.3/jquery.easyui.min.js" type="text/javascript"></script>
    <link href="../jquery-easyui-1.2.3/themes/default/easyui.css" rel="stylesheet" type="text/css" />
    <link href="../jquery-easyui-1.2.3/themes/icon.css" rel="stylesheet" type="text/css" />
    <%
        string id = "";
        if (Session["id"] != null)
        {
             id = Session["id"].ToString();
        }
    %>
     <script>
         $(function () {
             var  id = "<%=id %>";
             var opt = "<iframe id='summary' src='searchuser.aspx?id=" + id + "' width='1200px' height='1200px' ></iframe>";
             var art = "<iframe id='summary' src='Custor.aspx?id=" + id + "' width='1200px' height='1200px' ></iframe>";
             var col = "<iframe id='summary' src='dialogue.aspx?id=" + id + "' width='1200px' height='1200px' ></iframe>";
             $("#opt").append(opt);
             $("#art").append(art);
             $("#col").append(col);
         });
     </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
             <div style="width:20%;height:100%; float:left;">
         <asp:TreeView ID="TreeView1" runat="server">
             <Nodes>
                 <asp:TreeNode Text="对话列表" Value="新建节点">
                 </asp:TreeNode>
             </Nodes>
         
    </asp:TreeView>
        </div>
        <div id="tt" class="easyui-tabs" >
        <div title="对话界面" id="col" style="padding:20px;"> 
        </div>
        <div title="访客信息" id="opt" style="padding:20px;"> 
        </div>
        <div title="历史记录" id="art" style="padding:20px;"> 
        </div> 
        </div>
             <br />
        <div style="float:left">
                 <asp:ContentPlaceHolder id="ContentPlaceHolder1" runat="server">
        </asp:ContentPlaceHolder>
        </div>
    </div>
    </form>
</body>
</html>设置了3个选项卡 最后出来了5个 并且设置的3个选项卡点击的时候不进行专挑easyui界面