"Knock Knock - Luke" joke

Knock Knock!
Who's there?
Luke.
Luke who?
Luke through the keyhole and you'll see... Knock Knock
Who's there!
Luke!
Luke who?
Luke and see who it is! Knock Knock
Who's there!
Luke!
Luke who?
Luke before you leap! Knock Knock
Who's there!
Luke!
Luke who?
Lukecaracha!