document.getEle mentById(toggle[i]) has no properties

[swiftouch]

I'm getting an error message in FF2.0:

document.getEle mentById(toggle[i]) has no properties

The goal of the script is, when I hover my mouse over an image, to make one div element visible while making all the others div elements in the array, hidden.

thisDocId is the element to avoid hiding.

This is the script:
[HTML]<script>
function makeHidden(this DocId) {
var toggle = new Array();
toggle[0] = "about_us";
toggle[1] = "merchants" ;
toggle[2] = "associatio ns";
toggle[3] = "consumers" ;
toggle[4] = "newsandevents" ;

for (i=0;i<toggle.l ength;i++) {
if (toggle[i] != thisDocId) {
document.getEle mentById(toggle[i]).visibility="h idden";
}
}
} //end makeHidden function
</script>[/HTML]

This is part of the HTML:
[HTML]<a href="aboutus.h tml"><img src="images/H0m2.jpg" alt="" name="Image2" align="top" onmouseover='do cument.getEleme ntById("about_u s").visibility= "visible"; makeHidden("abo ut_us");' /></a>[/HTML]

So the idea is to display a <div> menu while toggling the other menus to "hidden";

[swiftouch]

I figured it out.

The problem code:

document.getElementById('about_us').visibility='visible';

The solution code:

document.getElementById('about_us').style.visibility='visible';

I left out style.

Funny how that took me 45 minutes to see. ARRRG!