send net message server to client

I'm coding this messenger like program, first creating a host/server in one program. Then connecting to it with a client program.
But I can only send messages from the client program to the host/server program. If if try to send a message to the client from the server i get a "Stream does not exist".
I cant post any source code right now, but if you need it i'll post it soon.
I'm using WriteString tcp_stream, "Message" to send the messages.

there needs to be a stream from client to server and from server to client.

the handle for the stream is local to the box

Ok now it works :) thanks for your help