[kh99]

OK, sorry - I guess that's why you posted in the Programming Discussion area.

Anyway, I think you want something like this:

PHP Code:

$groupid = 1; // set this to the group id you want
$users = $vbulletin->db->query_read("SELECT username FROM ".TABLE_PREFIX."user
                   WHERE usergroupid = $groupid");
$str = '';
$sep = '';
while ($user = $vbulletin->db->fetch_array($users))
{
    $str .= $sep . $user['username'];
    $sep = ', ';
}
// $str is comma separated list of users in $groupid
$vbulletin->db->free_result($users); 


That does one user group, so you can put that whole thing in a loop, or you could modify the query to get all groups at once and handle the separate lists in the while loop.

Also this only handles primary user groups and not membership in secondary groups. (And also I haven't tried this code at all).