user_count doesn't work

user online statistic works fine, but guest online doesn't work. there is only one guest
online all the time and that can't be true.

i found the code snippet, but i don't know where the error is:

PHP Code:

if( $this_user['login'] != 1 )
            {
                if( $this_user['id'] > 0 )
                {
                    $user_count++;
                    $names .= ($a) ? ", " : "";
                    $names .= $span_pre."<a href='./member.php?$session[sessionurl]&amp;u=".$this_user['id']."'>";
                    $names .= $this_user['prefix'].$this_user['name'].$this_user['suffix'];
                    $names .= "</a>".$span_suf;
                    $a++;
                }
                else
                {
                    $guest_count++;
                } 


everybody has the same prob, but nobody cares about it. why?

i'd like to know how many users are online.