A bar has three doors.

Drunk staggers in the front door, orders a beer. Bartender informs him that he can't serve those already intoxicated. Drunk staggers back out the front door.

Same drunk staggers in the side door. Is once again told he's too drunk to be served, staggers back out the side door.

Drunk crawls in the back door. Hoists himself up to the bar, takes a look at the bartender and says.... wait for it...

"Do you work at every bar in this town?"

(rim shot)

"The price of good shotgunnery is constant practice" - Fred Kimble