Hi,
I would not use MooTools or any Javascript at all if everything you
want to do is to swap an image.
If your HTML code is e.g.
<ul id="navigation">
<li><a href="/">Home</a></li>
<li><a href="subpage">A Page</a></li>
<li><a href="subpage2">Another Page</a></li>
</ul>
just use a CSS like
#navigation li a {
background: #fff url(images/navigation_bg.gif) no-repeat;
}
#navigation li a:hover {
background: #aaa url(images/navigation_bg_hover.gif) no-repeat;
}
Depending on your image you may want to define the width and height
CSS info of your link or list item. There are countless ways to refine
this but I'm sure there are some good tutorials out there.
I used a couple of "rollovers" on my site, all without any Javascript:
http://www.nugob.org . You better only use Javascript if it is
justified.
Cheers!
Anatol
