ListBox双击传值

<% @ Page language="c#" Codebehind="WebForm3.aspx.cs" AutoEventWireup="false" Inherits="TableStudy.WebForm3"  %>
<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"  >
< HTML >
     < HEAD >
         < title > WebForm3 </ title >
         < meta  content ="Microsoft Visual Studio .NET 7.1"  name ="GENERATOR" >
         < meta  content ="C#"  name ="CODE_LANGUAGE" >
         < meta  content ="JavaScript"  name ="vs_defaultClientScript" >
         < meta  content ="http://schemas.microsoft.com/intellisense/ie5"  name ="vs_targetSchema" >
         < script  language ="javascript" >
        <!--
            function Url(obj)
            {
                var sel=obj.options[obj.selectedIndex].text;
                window.open("IEPrint/main.aspx?param="+sel);
            }
        //-->
         </ script >
     </ HEAD >
     < body  MS_POSITIONING ="GridLayout" >
         < form  id ="Form1"  method ="post"  runat ="server" >
             < FONT  face ="宋体" >
                 < SELECT  id ="Select1"  ondblclick ="Url(this)"  style ="Z-INDEX: 101; LEFT: 176px; WIDTH: 184px; POSITION: absolute; TOP: 112px; HEIGHT: 96px"
                    size ="6"  name ="Select1"  runat ="server" >
                     < OPTION > aaaaaaaaaa </ OPTION >
                     < OPTION > bbbbbbbbbb </ OPTION >
                 </ SELECT >
             </ FONT >
         </ form >
     </ body >
</ HTML >