Hallo Semi !!
Probier mal das :
<html><head><title></title>
<script language = "javascript">
if (document.getElementById)
{document.write ("Ein neuer Browser<br>")}
else if (document.layers)
{document.write ("Ein alter Navigator<br>")}
else if (document.all)
{document.write ("Ein alter Explorer<br>")}
function verstecke()
{
if (document.getElementById)
{ document.getElementById("logo").style.visibility = "hidden"; }
else if (document.layers)
{ document.layers["logo"].visibility="hide";}
else if (document.all)
{logo.style.visibility="hidden"; }
}
function zeige()
{
if (document.getElementById)
{document.getElementById("logo").style.visibility = "visible"; }
else if (document.layers)
{ document.layers["logo"].visibility="show"; }
else if (document.all)
{ logo.style.visibility="visible"; }
}
</script>
</head><body>
<div id="logo" style="position:absolute; top:120; left:120"><img src="bild.gif"></div>
<a href="#" onclick ="verstecke()">Layer verstecken</a><br>
<a href="#" onclick ="zeige()">Layer zeigen</a>
</body></html>