Yup, it's called a JavaScript function. 
Code:
<html>
<head>
<script language="Javascript">
function change (picurl, picurl2) {
document.picture1.src = picurl;
document.picture2.src = picurl2;
}
</script>
</head>
<body>
<img src="image2_off.jpg" name="picture2">
<p>
<a href="page.html" onMouseOver="change('image_on.jpg','image2_on.jpg");" onMouseOut="change('image_off.jpg')">
<img src="image_off.jpg" name="picture1" border="0"></a>
</body>
</html>
Try that - replace the image names as needed - the mouseover should change the image it's on top of, as well as the one at the top of the page.
If you need me to walk you through it a bit more, let me know.
Bookmarks