Inside An Elevator                                     -      -      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      -      -

You are standing on a small wooden platform, surrounded by high stone
walls.  There is a panel attached to one corner of the platform, containing
a single red button with a large white arrow on it.  You have heard about
deivces such as this before, and you know that they employ a system of
pulleys to lift the platform up to the level above.  Unfortunately, this one
isn't too well designed, and can only give you a one-way trip.