Users online is in the iStore...Have you checked your database to see if the chat tables were created?

ooo, this has been solved...

ive made functionality which enable the user to change their screen name away from their login.

was all installed correctly, now, in the DB you save the sender or "from" as the users screen name not by the user login, which you use as the receiver 'to'. if they are not both the logins then the link is not correct and the messages dont displays between users.

force login =
private_chat.php:
$_SESSION['username'] = $current_user->user_login; // Must be already set

p.s. got users online, its a simple little thing but soo soo cool, thanks.