I'm Trying To Find the Name of a Movie

Does anyone know the name of a movie which I believe has Christopher Walken as an aspiring actor who in real life is something of a nerd, but when he gets a role he is transformed into whatever character he is playing on and off stage. I think I remember that one of his roles is Stanley in "Street Car" I thought it was called Thespian, but have not been able to find it under that name.