Thanks Friends!I make my chat system to work, It works like this:When a user A send new message to user B the message will be stored in a database and User B clicks a button it will check for new message from the database and it will display all the message he got. But this is not good as it adds load to the user to check each time for new message. I need to make the system to check with out awareness of the user and display the message how can I do that?, is AJAX helpful for this? If so pleas tell some hint how to use it?By the way there is a Connect function in PHP which is different from mysql_connect, socket_connect, hw_connect. It uses three parameters as connect(int Socket, sting Address,int Port).Have a nice Day