Dancin' Salesman(1988)

Two young salesmen spend their days selling learning materials. They walk and walk, but their performance doesn't improve, and they can't find a woman. In the meantime, one of them is attacked by a street thief and is seriously injured and loses his mind. This black-and-white film powerfully captures the sorrows of these men with a hodgepodge of action, slapstick, musicals and everything in between, backed by a riot of oldies, songs and commercials.