STAMFORD-A Norwalk man who supplied the crack cocaine that killed another Norwalk man last July was sentenced to four years in prison Friday. Eric Frank, 29, of Freedman Place pleaded guilty to second-degree manslaughter, second-degree assault, sale of narcotics and assault on a police officer at the Stamford courthouse. The sentence handed down by Judge Gary White carries an eight year term of special parole, which can immediately put Frank back in jail for almost any violation of the law once he is released.