We all are curious what happens behind the scenes on a set of a movie. Now you know from these behind the scene stories.
"While looking for a tattered coat for the character playing The Wizard in the Wizard of Oz, a costume assistant bought one from a second hand store. When the actor put the coat on he turned the pocket inside out - written in the pocket was the name L.Frank Baum who is the author of The Wizard of Oz books. Baum's widow later identified the coat as actually having belonged to her husband." Source