Displaying a list of users that are currently logged in" Stopped working

I use the code below from the "Displaying a list of users that are currently logged in" tutorial
Everything worked great then it stopped. Was there a change in the code that makes this not work?
Thanks in advance
<?php
$minutes=10;

$dispUsers=20;

$t=date('Y-m-d H:i:s', time()-$minutes60);

// display users who were active in last 10 minutes
$users=DBLookup("select count() from invusers where lastaccess > '".$t."'");

if ($users>0) {

$sql="select * from invusers where lastaccess > '".$t."'";

$rs=CustomQuery($sql);
if ($data = db_fetch_array($rs)) {

echo $users." active user(s): ".$data["username"];

}

$count=1;

while ($data = db_fetch_array($rs)) {

if ($count<$dispUsers) {

$count++;

echo ", ".$data["username"];

}

else {

echo " ...";

break;

}

}

}

?>