sending and receiving data from server to client and vice versa using indy9

Take a look at the Indy website.

http://adg.bmpcoe.org/IndySSL/

They have some good starter examples for you to learn from  :o)

Thanks. But i need a more detailed code with my problem. I havent found the exact server to client data sending like logging off the clients station.

to send data to the client within the server's "OnExecute" code you can just go
AThread.Connection.WriteLn('Please go away now');
and the client could see that and disconnect
s := IdTCPCLient1.readLn;
if s = 'Please go away now' then IdTCPClient1.Disconnect;

of course, you could just have the server disconnect the client...
AThread.Connection.Disconnect;

If you need to send a message to a client, but you are not within the onececute event, you could iterate through all the clients and send the message that way
eg.

    with IdTCPServer1.Threads.LockList do
    try
        for i := 0 to Count - 1 do
        begin
              if (
                   (TIdPeerThread(Items[i]).Connection.Socket.Binding.PeerIP = '127.0.0.1')
{if you know the port you wish to talk to, you could also check
                   and (TIdPeerThread(Items[i]).Connection.Socket.Binding.PeerPort = 12345)
Normally I'd have an "id" or "name" property set in teh ".Data" pointer (as an object) so I'd just find it that way
                  ) then TIdPeerThread(Items[i]).Connection.Writeln('I''m talking to you');
             
     finally
        IdTCPServer1.Threads.UnLockList;
     end;

I do not recall the commands to "logoff" a user's machine, but I think it's something like
ExitWindowsEx(EWX_LOGOFF + EWX_FORCE, 0);

but if you still wanted to be able to commiunicate if the client logs their machine off, then make this a service (which will run even if no one is logged on to the machine)

Thanks. Can you give me a working project for the server and client.
Im still having trouble. I implemented the code but still the client didnt receive the data sent
by the server. Sorry. Ill raise the points to 400. Thanks :)
Send it to my email: tirbanx@gmail.com