Come Fill the Cup (1951)

Alcoholic newspaperman Lew Marsh hits bottom, loses his job and is rehabilitated by Charley Dolan. After six years on the wagon he gets his job back and devotes himself to other recovering alcoholics. His boss enlists his help to sober up his nephew, Boyd Copeland, who has married Lew's old sweetheart. Boyd, who is involved with a cabaret singer and the mob, presents quite a challenge.