Hal understanding knock-knock jokes

[ssheetz]

Does anyone know how to make Hal tell and respond to knock-knock jokes?  He doesn't necessarily have to "get" them, just participate.  So if I say "Knock knock" he knows to say "Who's there?", "... who?", and then react.  Also could he randomly tell knock jokes from a list, provided that users respond correctly?  This must have been done before...