Invite friend: How to notify player to stop waiting?

Options
Hi, about inviting friend to join room, I have a problem like this.
On OnRoomListUpdate, if there is a room with specified name, I know there is player invite me to join that room. It is ok if I confirm YES. But if I want to confirm NO, how can I notify that player to stop waiting?
Any suggestions? Change the room properties? Or anythings else?