Who's there? (National Knock-Knock Day)

Everybody knows that today is Halloween, but did you also know that it's National Knock-Knock Day? National Knock-Knock Day is the day to make your most creative knock-knock joke and to share it with all. May be by the end of today we'll actually be able to find out "Who's there?"

Here's one:

Knock knock!
Who's there?
General Lee.
General Lee who?
General Lee I don't tell knock knock jokes, but I couldn't resist sharing some on National Knock Knock Day.

Celebrate National Knock-Knock Day with promotional door knob organizers from ePromos.
We'd like to hear your most creative knock-knock jokes.