Firefox Mouseover Problem

[kickedINtheHEAD]

so hab das zeug mal schnell runter geschrieben is also nur as notwendigste drinnen

Code:

<script type="text/javascript">
function change (Image) {
    document.getElementById('bild').src=Image;
}
</script>
<a href="#" onmouseover="change('2.gif')" onmouseout="change('1.gif')">link</a>
<img id="bild" src="1.gif" />