The Joker was looking at the door. Batman was on the outside of the door.
"Hey, door, do you want to hear a joke?" said the Joker.
"No, I don't want to hear them." said Batman, on the outside of the door.
"Okay then. Who was at the door?" asked the Joker, beginning his joke.
"What?" asked Batman, on the outside of the door.
"It was Batman!" laughed the Joker, ending his joke.
Batman then hit the Joker with the door.
"That's what happens when you mess with Batman and think he was the door." said Batman.