To talk openly in the room, just click in the 'white' bar at the bottom of the window, type in your text and then press the 'carriage return' or 'enter' key. If you wish to have a private conversation, or send private messages for a particular user(s) then you will need to double-click on a username from the panel to the left. Another window will pop-up in which your private conversation can take place. To end a private conversation, just close the window, and to exit the chat room you can either close the main window, or select the 'Room' option and then 'Close'.