Here are some randomly selected joke topics beginning with the letter 'D'
Door
Knock, knock.
Who's there?
Emmett.
Emmett who?
Emmett the front door, not the back one.
Door
Knock, knock.
Who's there?
Ima.
Ima who?
Ima gonna break down this
door if you don't open it!
Door
A cubicle is just a padded cell without a door.
Door
Knock, knock.
Who's there?
Icon.
Icon who?
Icon make you open the door.
Donkeys
How do you get five donkeys on a fire engine?
Two in the front, two in the back, and one on the roof going EE-AW-EE-AW.
Door
Knock knock,
Who's there?
Heywood.
Heywood who?
Heywood you open the door?
Door
Knock knock
Who's there?
Norma
Norma who?
Normally the butler opens the door.
Double
"Doctor, doctor< I keep seeing double."
"Take a seat please."
"Which one?"
Door
Knock, knock.
Who's there?
Major.
Major who?
Major mind up to open the door yet?