A newly commissioned second Lieutenant discovered that he had no coins
  at all for the soda machine.  He asked a passing enlisted man if he had
  change for a dollar.  "I'm pretty sure I do, hang on a sec buddy."
    "Just a minute !" snapped the Lieutenant.  "That's no way to reply to
  an officer. Now let's try it again.  Soldier, do you have any change ?"
    The enlisted man came to attention, saluted, and said, "No sir !"