树形菜单问题请教

初始化的时候树形菜单是展开的，可否初始化的时候二级子菜单是隐藏起来的，点击之后才展开。请高手赐教，不甚感激，谢谢！（代码如下）<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script>// Example: obj = findObj("image1");
function findObj(theObj, theDoc)
{
  var p, i, foundObj;
  
  if(!theDoc) theDoc = document;
  if( (p = theObj.indexOf("?")) > 0 && parent.frames.length)
  {
    theDoc = parent.frames[theObj.substring(p+1)].document;
    theObj = theObj.substring(0,p);
  }
  if(!(foundObj = theDoc[theObj]) && theDoc.all) foundObj = theDoc.all[theObj];
  for (i=0; !foundObj && i < theDoc.forms.length; i++) 
    foundObj = theDoc.forms[i][theObj];
  for(i=0; !foundObj && theDoc.layers && i < theDoc.layers.length; i++) 
    foundObj = findObj(theObj,theDoc.layers[i].document);
  if(!foundObj && document.getElementById) foundObj = document.getElementById(theObj);
  
  return foundObj;
}
</script>
<title>无标题文档</title>
<style type="text/css">
<!--
.emenu {
 background-image: url(e.gif);
 background-repeat: no-repeat;
 padding-left: 40px;
 cursor: hand;
}
.submenu {
 padding-left: 24px;
}
.file {
 background-image: url(ie.gif);
 background-repeat: no-repeat;
 padding-left: 18px;
 cursor: hand;
}
-->
</style>
</head><body>
<table width="200" border="0" cellspacing="0" cellpadding="1">
  <tr>
    <td class="emenu" onMouseUp="with(findObj('blue'))if(style.display=='none'){style.display='';this.style .backgroundImage='url(c.gif)'}else{style.display='none';this.style .backgroundImage='url(e.gif)'}">blue</td>
  </tr>
  <tr id="blue">
    <td class="submenu"><table width="200" border="0" cellspacing="0" cellpadding="1">
      <tr>
        <td class="emenu"onMouseUp="with(findObj('a'))if(style.display=='none'){style.display='';this.style .backgroundImage='url(c.gif)'}else{style.display='none';this.style .backgroundImage='url(e.gif)'}">a</td>
      </tr>
      <tr id="a">
        <td class="submenu"><table width="200" border="0" cellspacing="0" cellpadding="1">
          <tr>
            <td class="file">b</td>
          </tr>
          <tr>
            <td class="file">c</td>
          </tr>
          <tr>
            <td class="file">d</td>
          </tr>
        </table></td>
      </tr>
    </table></td>
  </tr>
  <tr>
    <td class="emenu" onMouseUp="with(findObj('flash'))if(style.display=='none'){style.display='';this.style .backgroundImage='url(c.gif)'}else{style.display='none';this.style .backgroundImage='url(e.gif)'}">flash</td>
  </tr>
  <tr id="flash">
    <td class="submenu"><table width="200" border="0" cellspacing="0" cellpadding="1">
      <tr>
        <td class="file">v</td>
      </tr>
      <tr>
        <td class="file">h</td>
      </tr>
    </table></td>
  </tr>
</table>
</body>
</html>