Man: Doctor, could you please write me a prescription for whiskey?
Doctor: Sure, but only if it's justified - like, for example, in case of a rattlesnake bite.
Man: And have you got a rattlesnake, Doctor?
Doctor: Yes, I most certainly do.
Man: Then let it bite me, and then you'll write me the prescription.
Doctor: (checks his journal) Okay, today is May the 5th. Come again on September the 16th. Until then, all the bites are taken.