Knock Knock Knock, knock. Who's there? Harry. Harry who? Harry up, it's cold out here!

Knockknock, who's there? It's Harry. Thankyou, Knockknock

Voldemort: Knock Knock Harry potter: Who's there? Voldemort: You know. Harry potter: You know who? Voldemort: Exactly!!!

I've decided to write a 'knock knock' joke about Jehovah's witnesses. "Knock, Knock, Knock , knock knock knock knock knock "