viewonline di phpBB nelal home

ciao a tutti io avevo ricevuto da un amico un codice per vedere guest nascosti e utenti registrati online utilizzando phpBB
prima ho incluso le librerie di phpBB con questo codice:

<?php
$me = "../informatica/"; 
//nome di questo file 
define('IN_PHPBB', true); 
$phpbb_root_path = '../community/'; // MODIFICARE IN ACCORDO ALLA TUA INSTALLAZIONE 
include($phpbb_root_path . 'extension.inc');  // Inclusione nella pagina delle librerie necessarie
include($phpbb_root_path . 'common.'.$phpEx); 

// 
// Start session management 
// 
$userdata = session_pagestart($user_ip, PAGE_INDEX); 
init_userprefs($userdata); 
// 
// End session management 
//
include "banners.php";
include "../community/config.php"; 
?>

poi il vero codice per gli users online è questo:

<?php
$db = mysql_connect($dbhost, $dbuser, $dbpasswd) or die ("Connessione        al database non riuscita");
mysql_select_db($dbname, $db) or die ("Selezione del database non              riuscita"); 
 $sql = "SELECT u.user_id, u.username, u.user_allow_viewonline, u.user_level, s.session_logged_in, s.session_time, s.session_page, s.session_ip 
   FROM ".USERS_TABLE." u, ".SESSIONS_TABLE." s 
   WHERE u.user_id = s.session_user_id 
      AND s.session_time >= ".( time() - 300 ) . " 
   ORDER BY u.username ASC, s.session_ip ASC"; 
if ( !($result = $db->sql_query($sql)) ) 
{ 
   message_die(GENERAL_ERROR, 'Could not obtain regd user/online information', '', __LINE__, __FILE__, $sql); 
} 

$guest_users = 0; 
$registered_users = 0; 
$hidden_users = 0; 

$reg_counter = 0; 
$guest_counter = 0; 
$prev_user = 0; 
$prev_ip = ''; 

while ( $row = $db->sql_fetchrow($result) ) 
{ 
   $view_online = false; 

   if ( $row['session_logged_in'] ) 
   { 
      $user_id = $row['user_id']; 

      if ( $user_id != $prev_user ) 
      { 
         $username = $row['username']; 
         if ( $row['user_allow_viewonline'] ) 
         { 
            $registered_users++; 
         } 
         else 
         { 
            $hidden_users++; 
         } 
         if ( $row['user_allow_viewonline'] || ($row['user_id'] == $user->data['user_id']) || ($user->data['user_level'] == ADMIN) || ($user->auth(POST_FORUM_URL, 'auth_mod', intval($row['session_page'])) && ($row['user_level'] != ADMIN)) ) 
         { 
            $view_online = true; 
            $style = isset($user_levels[ $row['user_level'] ]) ? $user_levels[ $row['user_level'] ]['style'] : $user_levels[USER]['style']; 
            $username = sprintf(($row['user_allow_viewonline'] ? (empty($style) ? '%s' : '<span' . $style . '>%s</span>') : '<i' . $style . '>%s</i>'), $row['username']); 
         } 
         else 
         { 
            $view_online = false; 
         } 
         $which_counter = 'reg_counter'; 
         $which_row = 'reg_user_row'; 
         $prev_user = $user_id; 
      } 
   } 
   else 
   { 
      if ( $row['session_ip'] != $prev_ip ) 
      { 
         $username = $lang['Guest']; 
         $view_online = true; 
         $guest_users++; 
    
         $which_counter = 'guest_counter'; 
         $which_row = 'guest_user_row'; 
      } 
   } 

   $prev_ip = $row['session_ip']; 

   if ( $view_online ) 
   { 
      if ( ($row['session_page'] < 1) || !$user->auth(POST_FORUM_URL, 'auth_view', intval($row['session_page'])) ) 
      { 
         switch( $row['session_page'] ) 
         { 
            case PAGE_INDEX: 
               $location = $lang['Forum_index']; 
               $location_url = "index.$phpEx"; 
               break; 
            case PAGE_POSTING: 
               $location = $lang['Posting_message']; 
               $location_url = "index.$phpEx"; 
               break; 
            case PAGE_LOGIN: 
               $location = $lang['Logging_on']; 
               $location_url = "index.$phpEx"; 
               break; 
            case PAGE_SEARCH: 
               $location = $lang['Searching_forums']; 
               $location_url = "search.$phpEx"; 
               break; 
            case PAGE_PROFILE: 
               $location = $lang['Viewing_profile']; 
               $location_url = "index.$phpEx"; 
               break; 
            case PAGE_VIEWONLINE: 
               $location = $lang['Viewing_online']; 
               $location_url = "viewonline.$phpEx"; 
               break; 
            case PAGE_VIEWMEMBERS: 
               $location = $lang['Viewing_member_list']; 
               $location_url = "memberlist.$phpEx"; 
               break; 
            case PAGE_PRIVMSGS: 
               $location = $lang['Viewing_priv_msgs']; 
               $location_url = "privmsg.$phpEx"; 
               break; 
            case PAGE_FAQ: 
               $location = $lang['Viewing_FAQ']; 
               $location_url = "faq.$phpEx"; 
               break; 
            default: 
               $location = $lang['Forum_index']; 
               $location_url = "index.$phpEx"; 
         } 
      } 
      else 
      { 
         $location_url = $config->url('index', array(POST_FORUM_URL => $row['session_page']), true); 
         $location = $forum_data[$row['session_page']]; 
      } 

      $row_color = ( $$which_counter % 2 ) ? $theme['td_color1'] : $theme['td_color2']; 
      $row_class = ( $$which_counter % 2 ) ? $theme['td_class1'] : $theme['td_class2']; 
      $$which_counter++; 
   } 
} 

$parzial_user = sprintf($l_r_user_s, $registered_users) . sprintf($l_h_user_s, $hidden_users); 
$parzial_guest = sprintf($l_g_user_s, $guest_users)); 
$tot_online_user = $parzial_user + $parzial_guest;
?>

però il codice mi da sempr elo stess errore anke modificando le varie linee e l'errore è questo:
Fatal error: Call to a member function on a non-object

beh ti sei assicurato che nella pagina dove inserisci il codice siano presenti le variabili
$dbhost, $dbuser, $dbpasswd e $dbname?

in caso contrario, al posto di queste inserisci rispettivamente localhost, skatekool, tuapass e my_skatekool

ciao!!
giaco