A customer walks into a shop and asks: ‘Does this shop have any fish?’
The sales assistant replies: ‘No. This is the shop that doesn’t have any meat. The shop that doesn’t have any fish is next door!’
(From an article by Jonathan Waterlow, who wrote a book on Soviet jokes during the time of Stalin)
This joke, at least in the way it is translated, doesn’t really work in English the way it does in Russian. The transition between the two lines in the dialog is too abrupt, too unmotivated. The Russian joke works because of the negation in the question («У вас нет рыбы/мяса?»). I don't know whether there is a natural way to express this in English. "You don’t happen to have any fish, do you" is probably the closest that comes to mind, but how natural is it coming from a customer?