Title: Remote Commands?

Im a complete noob when it comes to computercraft and i was wondering how i would make a simple rednet remote control for a server.

EX: i have multiple client computers that will send commands to 1 server and that server would do those commands. On the server i have 2 programs Up and Down and i want the clients to be able to use the command Up/Down and it will tell the server to do that command.

Thanks in advance :)/>