Stole this from a Doc's blog, but have forgotten who's it was. Sorry about that. This joke tickled me no end...
A woman walks into a pharmacy and goes straight up to the pharmacist, looking him directly in the eye.
"I need to buy some cyanide," she says.
"Why?" asks the pharmacist.
"I want to poison my husband."
The pharmacist is aghast.
"You can't do that! I can't sell you cyanide! The police will come; you'll go to jail; I'll lose my license! I can't give you any cyanide!"
The woman reaches into her purse and pulls out a photograph of her husband in bed with the pharmacist's wife.
"Ah," says the pharmacist. "You didn't tell me you had a prescription."