A man who wants to murder his wife goes into a pharmacy and asks for cyanide.
“I’m sorry sir, but I can’t give you cyanide just like that. “
Without a word, the man takes out his wife’s photograph and holds it in front of him.
The pharmacist apologizes, “My mistake, I didn’t realize you had a prescription. “
This joke is included in the Black Book of Jokes. You can order it from here.