Why doesn't this work correctly in FireFox?

[John Kotuby]

Hi all,

I have created an ASPX page in VS 2008 that appears inside of an IFRAME
inside a standard HTML page. Because it loads from an external site and is
database driven, the first load takes a few seconds. As a result I have
placed an absolutely positioned <DIVelement that is built into the HTML
page that uses an animated GIF and a "Please Wait" message.

When the IFRAME finishes loading a javascript function is called to change
the Visibilty of the DIV to hidden. All this works fine with IE but in
Firefox the DIV remains visible. Below is the relevant code from the HTML
page.

Can anyone tell me why this doesn't work in FireFox?

-----------------------------------------------------------------
<td width="775" valign="top">
<iframe width="99%" style="z-index:1" height="820px" marginheight="4px"
marginwidth="4px" id="ifSearch" scrolling="no"
src="http://www.motillia.net/search.aspx" onload="iframe_onload();">
</iframe>
</td>

<script type="text/jscript" language="javascript">
function iframe_onload()
{
var theWaitCell = document.getElementById('Wait1');
theWaitCell.style.visibility = "hidden";
}
</script>

<div id="Wait1" style="visibility: visible; position: absolute; top: 40%;
left: 40%">
<table id="WaitTable1">
<tr>
<td id="WaitCell1" align="center" valign="middle"
style="background-color: Silver;
border-width: 4px; border-style: outset; color: White;
height: 100px; width: 300px;
font: vedana bold 16px">
<img alt="downloading" src="images/loadingAnimation.gif" />
<br />
Search Tool Initializing...
</td>
</tr>
</table>
</div>
--------------------------------------------------------------

Thanks for any help with this.