Got Quackers?

A duck walks into a bar and asks the bartender for some quackers. The bartender explains that the bar doesn't have any quackers.
The next day, the same duck walks into the bar and asks the bartender for some quackers. The bartender again explains that the bar doesn't serve quackers.
Sure enough, the very next day, the duck again walks into the bar and asks for some quackers. The bartender screams at the duck, "If you come in here one more time, I'm going to nail your beak into the wall with a hammer and some nails! "
A few days pass, and then the duck walks into the bar again.The bartender notices the duck and says, "I'm warning you!"
The duck replies, "Do you have a hammer?"
The bartender replies, "No!"
The duck asks, "Do you have any nails?"
The bartender replies, "No!"
The duck grins and asks, "Do you have any quackers?"