Network Messaging (MS SQL SERVER 2000)

Hi all,

I'm working with D6, MS SQL SERVER 2000 and ADO.I have a WINDOWS NT SERVER
4.0 and three WINDOWS XP as it's clients. In my project, there is a form
which shows records of a simple table. Every client can see this form and
view or modify that table. Now I want a way to show online information in
this form when for example :

   Client 1 and 2 : Have opened the form and are viewing the records.

   Client 3 : Has opened the form and is editing the data, when this user
finishes it's job, the transaction will be commited and the records in the
server will be updated, so a message should be sent from server to other
open connections (Client 1 & 2) to tell them that they must refresh
themselves, and then, Client 1 and 2 get this message and do the necessary
works.

Can anybody help me about this?

I know in the client application, I can regularly check the last state of
the table in server, but this will cost network trafic and too much
unnecessary process in the program. The best way is "messaging system", but
how can we send a message from the server to all the clients, and, more
important part, how can we get these messages in client application and
handle them?

Your early reply is appreciated.

Best regards

Hamed F.