Installation:
Upload files to the correct location like in that code below:
stupid.gif to images/ folder and float-button-reg.js to clientscript/ folder

If you want the main forum page only insert that code to forumhome template and if u want on all pages then insert that code in footer template.

Insert the following code:

<vb:if condition="$show['guest']">
<script type="text/javascript" src="clientscript/float-button-reg.js"></script>
<style type="text/css">
#topbar
{   
 PADDING-TOP: 100px;
 PADDING-BOTTOM: 5px;
 PADDING-RIGHT: 5px; 
 PADDING-LEFT: 5px;
 VISIBILITY: hidden;
 WIDTH: 350px;
 FONT-FAMILY: Tahoma;
 POSITION: absolute;
}
</style>  <div id="topbar"> <table width="100%"> <tr> <td width="99%"> <a href="register.php"><img style="float: left" src="images/bormotuhi.net.gif" border="0"></a> </td> </tr> </table> </div>

SAVE and enjoy :)