TCP Server/Client Help

[Atheist]

Thanks. The sending & receiving message works now.

Another question is how do I handle when the client exits the program or lose it's internet connection?
I tried sending "DISCONNECT" & ControlChars.Cr to the Server but an exception still appears.

Well, seeing as you can never be certain that a connection still exists at the very time you are trying to send/receive something, I believe your only real solution is to use error handling with Try-Catch blocks.

And let's say if I have few users connected to the server, how do I send a specific message to a certain user instead of broadcasting it?

You will have to think off a good application layer protocol for your client-server project, that is...define the language in which the server and client will communicate.
Perhaps you could choose to specify the name of the receiver first in the message, and then the text to be sent, and let the server parse out the receiver name and route the message on to that particular client. Thats one way to go about it.