Lieutenant Nancy Mendenhall was a character which appeared in the Season 8 M*A*S*H TV series episode "Bottle Fatigue". Nurse Mendenhall was played by actress Shelley Long, who would go on to co-star as Diane Chambers on the hit NBC-TV sitcom series Cheers.
About Nurse Mendenhall and Hawkeye's "sobriety"
Hawkeye is so shocked he decides, then and there, to stop drinking, after finding out at the Officers' Club with the rest of the Medical Staff after a long surgery strech, that his bar tab was over $40. After earning a round of laughter from everyone, he insists its not forever - just for a week, to prove to himself that he can do it.
When Hawkeye has a date with Lt. Mendenhall, who's the lovely looking new nurse in camp, she is, at first smitten with him and his sense of humor, but on their private date in the supply room, Hawkeye, in his new found "sobriety", which was also driving the whole camp nuts, quickly ruins it by making snide comments about her drinking, even citing when had drank her third glass of wine. Lt. Mendenhall, before storming off in disgust, says to him, "If I recall, this little tet-a-tet was your idea, not mine...If I would have known that was going to receive a temperance lecture... I would have made a date with someone more fun...like a cadaver!"