A talking duck waddles into a stop 'n' rob and asks the sales guy, "Got any grapes?"
"No," answered the guy.
The duck waddles out. A little later it returns and asks, "Got any grapes?"
The clerk replies, "No! Like I told you fifteen minutes ago--I don't have any grapes!"
The duck leaves. Fifteen minutes later he's back again, asking, "Got any grapes?"
In a real snit now, the clerk yells, "No I don't have any goddamn grapes! You come back in here again, I'll nail your webbed feet to the floor!"
Later that day the duck comes back and asks the guy, "Got any nails?"
The guy says "NO!"
The duck replies, "Good! Got any grapes?"