What the Doctor Ordered...

This woman walks into a pharmacy and asks the pharmacist for some arsenic.

He asks "What for?"

She says "I want to kill my husband".

He says "Sorry, I can't do that."

She then reaches inter her handbag a pulls out a photo of her husband in bed with the pharmacist's wife and hands it to him.

He says, "You didn't tell me you had a prescription..."