place this in your global.php

~~~~~~~~~~
// ###################### Check Usersonline #######################
$vars=$DB_site->query("SELECT user.username, user.userid FROM user, session WHERE session.userid=user.userid");
while($var=$DB_site->fetch_array($vars)) {
$varcache["{usersonline}"] .=' <a href="member.php?action=getinfo&userid='.$var[userid].'">'.$var[username].'</a>';
}
~~~~~~~~~~

require global.php

place in your templates {usersonline} (the replace variable)

e.g.:

usersonline.php
~~~~~~~~~~
<?

require("global.php");
eval("echo dovars(\"".gettemplate("usertest")."\");");

?>
~~~~~~~~~~

template usertest
~~~~~~~~~~
<table>
<tr>
<td>{usersonline}</td>
</tr>
</table>
~~~~~~~~~~

sorry for the bad english i am a german guy