拖拽事件 急 加班 求高手解决

<%--
Generator: 毕晓东 
Creation Data:  2008-10-7
Original Author:  毕晓东
name:/jsp/utility/middle.jsp
Function：Portal系统页面
--%>
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%
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>
<title>middle.jsp</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">
<style type="text/css">
<!--
body {
margin-left: 0px;
margin-top: 0px;
margin-right: 0px;
margin-bottom: 0px;
border-left: 0px;
}
-->
</style>
</head>
<script language="JavaScript" src="../js/middle.js"></script>
<script language="JavaScript" src="../js/jquery-1.4.4.min.js"></script>
<script language="JavaScript">
function fous(){
var test = document.getElementById("tb1");
test.focus();
var x=event.screenX;
window.parent.cen.cols=x+",16,*";
window.parent.treeFrame.document.all.tree_div.firstChild.firstChild.style.width=(x-20)+"px";

//stest.ondrag();
    //test.setCapture();
//test.setDrag();
}
</script>
<body  >
<table width="16" height="100%" cellspacing="0" cellpadding="0"
border="0">
<tr>
<td height="13" background="../images/mis_main_top_down3.jpg""></td>
</tr>
<tr>
<!--  style="background:url('../images/mis_main_midline_bar.jpg');height:55px; width:60px; margin: 0px;" -->

<td style=" cursor:move; position:fixed ;" id="tb1" 
background="../images/mis_main_midline_bg.jpg"
  ondragstart="onFocus();setCapture();"  ondrag="fous()"     ondragend="releaseCapture();" ><div 
id="imghiddetop" valign="middle" align="center" 
style="background-image: url(../images/mis_main_midline_bar.jpg); width: 30px; height: 70px;
    position:fixed ">
<!--  
<img id="imghiddetop" src="../images/mis_main_midline_bar.jpg" hspace="0" vspace="0"
align="center" onclick="isShowleft()"  ondrag="fnDrag();" />
-->
</div>
</td>

</tr>
<tr>
<td height="12" background="../images/mis_main_bottom3.jpg""></td>
</tr>
</table></body>
</html>拖拽那个TD 可以移动 但是现在有个小BUG  就是拖动第一次的时候无效 再拖动一次 就有用了 求解决 没有分了 见谅