Dog's Life: The grandchildren of Hubert Selby Jr.'s ''Last Exit to Brookling'' are not well. Director John Knapich and Co-writer Tom Kelley introduces us to an urban world of hope and heartbreak in this story of two bargain basement dreamers. Set in a working-class Brooklin and featuring a colorful array of intriguing misfits, this compassionately told comic-drama, about the interviewed fates of a troubled young man and a dim-witted janitor, observes an urban America both fortified and betrayed by two-bit fantasies.