Ultimate Prediction Board - Wood

The audience is asked to develop a story with the details recorded on a single chalkboard, in colored chalk by the magician.

Immediately after, the magician opens the upper door to reveal that his prediction, written in white chalk, matches perfectly with the spectators freely chosen words.

This is an entirely unique principle that eliminates the drawbacks of every of prop of this nature.

NO Force!  NO Double Writing!
NO Assistants!  NO Electronics!
NO one ahead!  NO loading the prediction from tables or envelopes, etc.!

Just write the spectator's answers and the magic is done! The most direct and straightforward principle possible.
There is NO other effect in the world that can meet these standards!
18? tall X 12? wide x by 1/5? thick