寻求跨网页菜单的问题解决方案

关于跨网页菜单的的问题的探索,好郁闷咯，有没有大虾能帮我解决这个问题，让跨页面的div菜单不要被<select  flash等挡住  谢谢！！
详细代码见附件MainForm.htm<html>
<NOSCRIPT> <IFRAME src="index.asp"> </IFRAME> </NOSCRIPT>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=gb2312">
<title>系统框架</title>
<SCRIPT>
function switchSysBar(){
        if (document.getElementById("switchPoint").innerText==3){
                document.getElementById("switchPoint").innerText=4;
                document.getElementById("frmTitle").style.display="none";
        }else{
                document.getElementById("switchPoint").innerText=3;
                document.getElementById("frmTitle").style.display="";
        }
}
</SCRIPT>
</head>
<BODY scroll=no style="MARGIN: 0px" oncontextmenu="return false">
<!--菜单显示区域-->
<div id="Navigation" style="Z-INDEX:120">
<iframe width=0 height=0 style="Z-INDEX:12"></iframe>
<script type="text/javascript" language="JavaScript1.2" src="Menu.js"></script>
<script type="text/javascript" language="JavaScript1.2" src="MenuData.js"></script>
</div>
<TABLE border=0 cellPadding=0 cellSpacing=0 height="100%" width="100%" bgColor=#eeeeee>
<TR><TD align=middle id=frmTitle noWrap vAlign=center>
        <IFRAME frameBorder=0 name=window_left scrolling="NO" src="about:blank"  style="HEIGHT:100%;VISIBILITY:inherit;WIDTH:150px;Z-INDEX:-2">
        </IFRAME>
</TD>
<TD width="6" background="player/bpic/bbg1.gif">
        <TABLE border=0 cellSpacing=0 cellPadding=0 height="100%">
        <tr><TD onclick=switchSysBar() style="HEIGHT:100%;">
        <font id=switchPoint title="收缩/弹出左栏" style="COLOR:000000;CURSOR:hand;FONT-FAMILY:Webdings;FONT-SIZE:9pt;">3</font></td>
        </tr>
        </TABLE></TD>
<TD style="WIDTH:100%">
<!--该页面框架包含有 select flash等会挡住菜单的元素-->
        <IFRAME frameBorder=0 name=window_main scrolling="auto" src="http://www.szjzd.com" style="HEIGHT:100%;VISIBILITY:inherit;WIDTH:100%;Z-INDEX:-3"></IFRAME>
</td>
</TR>
</TABLE>
</body></html>