Hilfe bei JavaScript Layer AD Script

<script language="JavaScript1.2">
var ns4=document.layers
var ie4=document.all
var ns6=document.getElementById&&!document.all



function hidebox(){
if (ie4||ns6)
crossobj.style.visibility="hidden"
else if (ns4)
document.showimage.visibility="hide"
}


function versteck() {
crossobj=ns6?document.getElementById("showimage"):document.all.showimage;
hidebox();
}

window.setTimeout("versteck()", 5000);
</script>

<br><br>
<form method="POST">
   <p><select size="1" name="D1">
   <option>fsdfsdfsdfsdf</option>
   <option>sdfsdfdsf</option>
   </select><input type="submit" value="Absenden" name="B1"><input type="reset" value="Zurücksetzen" name="B2"></p>
</form>

<div align="center" id="showimage" style="position:absolute;left:10;top:20">

<table border="0" width="100" bgcolor="#CCCCCC" cellspacing="0" cellpadding="2">
<tr>
  <td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="0"
  height="36">
    <tr>
      <td id="dragbar" style="cursor:hand" width="100%"><ilayer width="100%" onSelectStart="return false"><layer width="100%" onMouseover="dragswitch=1;if (ns4) drag_dropns(showimage)" onMouseout="dragswitch=0"><font face="Verdana"
      color="#FFFFFF"><strong><small>Anzeige</small></strong></font></layer></ilayer></td>
      <td style="cursor:hand" valign="middle"><a href="#" onClick="hidebox();return false"><b><font color="#f5f5f5">x</font></b></a></td>
    </tr>
    <tr>
      <td width="100%" bgcolor="#FFFFFF" style="padding:4px" colspan="2">

<!-- Inhalt ---->

<IMG SRC="http://www.google.de/intl/de_de/images/logo.gif" width="400" height="400">
<!-- Inhalt ---->

</td>
    </tr>
  </table>
  </td>
</tr>
</table>
</div>