Change for a dollar

Corporal Conroy needed to use a pay phone, but didn't have change for a dollar.

He saw Private Duncan mopping the base's corridor floors, and asked him, "Soldier, do you have change for a dollar?"

Private Duncan replied, "Sure."

The Corporal turned red.

He said, "That's no way to address a superior officer!

Now let's try it again.

Private, do you have change for a dollar?"

Private Duncan replied, "No, SIR!"