javascript show and hide does not work with mozilla

Hi,
I have a code that works with IE but not with Mozilla. Div tags cannot be shown and hidden. Here are the most important parts:
...
function MM_showHideLayers() {
if(tp > 0 || bp > 0 || up > 0)
return;
var i,p,v,obj,args=MM_showHideLayers.arguments;
for (i=0; i<(args.length-2); i+=3) if ((obj=MM_findObj(args[i]))!=null) { v=args[i+2];
if (obj.style) { obj=obj.style; v=(v=='show')?'visible'v=='hide')?'hidden':v; }
obj.visibility=v;
obj.display=((v=='visible')?''(v=='hidden')?'non e':v)); }
}

var tp=0, bp=0, up=0;
function MM_stayShownLayer(imgName) { //v6.0
ClearSelection();
MM_showHideLayers(imgName,'','show');

if(imgName == 'i001'){
tp = 1;
document.getElementById('frmSelection').txtSelecti on.value = "Tri-Point Series";
}else if(imgName == 'i002'){
bp = 1;
document.getElementById('frmSelection').txtSelecti on.value = "Bi-Point Series";
}else if(imgName == 'i003'){
up = 1;
document.getElementById('frmSelection').txtSelecti on.value = "Uni-Point Series";
}
document.getElementById('frmSelection').txtImage.v alue = imgName;
}
...
<div id="i001" style="position:relative; width:200px; height:115px; z-index:1; left: 0; top: 0; visibility: hidden; display:none;"><img src="images/i001.jpg" width="487" height="287" border="0" usemap="#Map5"></div>

<div id="i002" style="position:relative; width:200px; height:115px; z-index:2; left: 0; top: 0; visibility: hidden; display:none;"><img src="images/i002.jpg" width="487" height="287" border="0" usemap="#Map6"></div>

<div id="i003" style="position:relative; width:200px; height:115px; z-index:3; left: 0; top: 0; visibility: hidden; display:none;"><img src="images/i003.jpg" width="487" height="287" border="0" usemap="#Map7"></div>
...
<form id="frmSelection" action="step2.php" method="post">
<font face="Arial, Helvetica, sans-serif" size="2">Cabinet Style
Selected</font>
<input type="text" name="txtSelection" value="<?php echo ((isset($_SESSION['step1SelText'][$cabindex])) ? $_SESSION['step1SelText'][$cabindex] : 'not yet selected') ?>" readonly>
<input type="hidden" name="txtImage" value="<?php echo ((isset($_SESSION['step1SelImg'][$cabindex])) ? $_SESSION['step1SelImg'][$cabindex] : '') ?>" readonly>
<font face="Arial, Helvetica, sans-serif" size="2" color="#999999">(Click
on icon to select)</font>
</form>
...

Thanks in advance!
Nima

Maybe I should have clarified the issue more: On mouse over showing , and hiding on mouseout works, just that the form selection and the image stays on click doesn't work with mozilla.

Try try using the "display" property rather than "visibility". Not sure if this will work, but worth a try.