I have a series of images that I would like to toggle on and off based upon mouseclick.

(for example)
a_on.gif
a_off.gif
b_on.gif
b_off.gif
etc...
These images are part of a long string of menu items on the page (let's say 30). When clicked they pass a javascript variable to load new information into another area of the page. (this works) But I'd like to make the menu more modular and not have to use the current method my limited programming capacity has left me with.

Right now I'm using div's and using a javascript to change the bg image of the div - With a transparent button over the image to allow for click.
(it's cheating but it works!)

IN THE HTML
<a href="#" onmouseover="javascript:WhoActivate();" onmouseout="javascript:WhoDeActivate();">Who We Are</a>

IN THE JS
function switchvis(id) {
if(document.getElementById(id)){
var ele = document.getElementById(id);
if(ele.style.visibility=="hidden"){
ele.style.visibility="visible";
}else{
ele.style.visibility="hidden";
}
}
}

//and then parse something like...

document.getElementById( 'divname' ).style.

//to change the bg image of the div.

I appreciate the help.

z