To challenge a remote player for a match proceed as follows:
Check who is online using the Who function from the Internet menu
Move the mouse cursor over the player you want to challenge and press the right mouse button.
From the popup menu select: Challenge -> player
This sends a match request to player
When player accepts the match request you are ready to play.
When someone challenges you, use the accept or decline command to accept or decline the match request. If there is more then one challenge the challenges are labeled with a name and number. Use this name or number in the accept or decline command.