Hallo,
<script type="text/javascript">
var zIndex = 100;
function up(what){
zIndex++;
what.style.zIndex = zIndex;
}
</script>
<div style="position:absolute; top:100px; left:100px; z-index:1; border:thin solid #804000;" onmouseover="up(this)">
<b>1.</b><img src="hund.gif" width="208" height="181" border="0" alt="Hund"></div>
<div style="position:absolute; top:130px; left:150px; z-index:4; border:thin solid #804000;" onmouseover="up(this)">
<b>2.</b><img src="hund.gif" width="208" height="181" border="0" alt="Hund"></div>
Hab's nicht getestet, sollte aber eigentlich gehen.
Grüße
Michael