可折叠左栏导航

<script type="text/javascript" language="javascript">
<!--
function ExpandContents(controller)
{
    mainFrame = parent.document.getElementById("mainFrame");
    if (mainFrame.cols == "150,10,*")
    {
        //已经展开，收缩之，并更换控制指示
        mainFrame.cols = "0,10,*";
        controller.src = "controller_expand.gif";
        controller.alt = "展开";
    }
    else
    {
        //已经收缩，展开之，并更换控制指示
        mainFrame.cols = "150,10,*";
        controller.src = "http://www.cftea.com/c/2007/04/controller_collapse.gif";
        controller.alt = "折叠";
    }
}
-->
</script>
<table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0">
  <tr>
    <td valign="middle" background="controller_bg.gif">
        <img src="http://www.cftea.com/c/2007/04/controller_collapse.gif" alt="折叠" id="controller" />
    </td>
  </tr>
</table>