Once there was a night watchman who had been caught several times sleeping on the job. The boss issued the final warning. On the next night he was caught with his head on his hand and his elbows on the desk.
"Aha, I've caught you again," exclaimed the boss. The watchman's eyes popped open immediately and he knew what had happened. Being a quick thinking man, he said one word before looking up at the boss. The boss apologized profusely and went home. What was the one word?