stramonium - 2014-04-11

Hi , i downloaded AJAX-Chat-0.8.7-smf for my smf forum.
I extracted the directory "chat" and uploaded on my forum's main directory .
I execute www.mydomain/chat/intall.php . It's all ok . Database table created .
Erased install.php file i try to enter in chat ...
The main page of ajax chat appear , but no user connected. If I try to send message "Hi" ,no message was poted in public channel .
The chat is compley inactive .
How i can resolve ?
Thanks