Danno: Knock-knock.
You: Who’s there?
Danno: Harding.
You: Harding who?
Danno: Knock-knock.
You (already growing weary): Who’s there?
Danno: Harding.
You (annoyed, but committed): Harding who?
Danno: Knock-knock.
You (realizing this is some bizarre variation on the old banana gag): WHO’S THERE?
Danno: Warren G.
You (relieved): Warren G who?
Danno: Warren G glad I didn’t say Harding again?
More Presidential and holiday ukulele here.