...
<head>
...
<script type="text/javascript">
zoom = new Image;
zoom.src = 'images/imagemap_detail.png';
function afficher_detail(img, alt) {
document.getElementById('detailDiv').innerHTML = '<img src="'+img.src+'" alt="'+alt+'" />';
}
</script>
</head>
<body>
...
<map id="themap">
<area href="javascript:afficher_detail(zoom, 'zoom sur le detail');" alt="zoom sur ce detail" coords="5,5,95,195" shape="rect" />
</map>
<img src="images/imagemap.png" alt="image map" usemap="#themap" width="300" height="200" /><br />
<div id="detailDiv"></div>
...
</body>
...