non va...ho provato ha inserire un'immagine e a mettere hidden il layer ma nulla



codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
    <title>Documento senza titolo</title>
    <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
    
    <script type="text/javascript">
    function closeoverlay() {
      document.getElementById('overlay').style.display = 'none';
    
    }
    function openoverlay() {
      document.getElementById('overlay').style.display = 'block';
    
    }
    </script>
</head>
<body onload="openoverlay(); setTimeout('closeoverlay()', 15000);">
<div id="overlay" style="position:absolute; top:20px; left:100px; width:452px; height:200px; z-index:100; display: block; visibility: hidden;">
[ X ]
[img]/png/productronica2005.png[/img]</div>



Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Donec suscipit turpis dictum 
leo. Aenean dignissim, diam nec dignissim pretium, elit arcu sollicitudin ante, 
dapibus lobortis pede sapien vitae metus. Nam placerat. Suspendisse eu arcu. 
Etiam dictum, dolor nec fringilla dignissim, odio felis scelerisque tellus, lobortis 
interdum dolor justo sit amet eros. Nullam ante est, posuere vel, molestie luctus, 
faucibus quis, nisi. 
</p>



Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Donec suscipit turpis dictum 
leo. Aenean dignissim, diam nec dignissim pretium, elit arcu sollicitudin ante, 
dapibus lobortis pede sapien vitae metus. Nam placerat. Suspendisse eu arcu. 
Etiam dictum, dolor nec fringilla dignissim, odio felis scelerisque tellus, lobortis 
interdum dolor justo sit amet eros. Nullam ante est, posuere vel, molestie luctus, 
faucibus quis, nisi. 
</p>

</body>
</html>