A nurse goes to talk to her doctor in a panic:
"oh my gawd, doctor, we mixed up a couple of patient accounts and I don't know which is which!", she says.
"How did they get mixed up?", he asks.
"We had two people in here last week named Harold Jones, and I don't know which one is which!"
"What were their results?"
"One of them has Alzheimers, and the other has herpes!", she tells the doctor.
He thinks for a minute and then tells her, "Do this: call the first Mrs. Jones and tell her we still need to run a couple test. Have her tell her husband to take a walk around the block and to call us an hour after he leaves."
"What do I tell her when she calls?", she asks.
"If her husband isn't back from his walk yet, tell her that he has Alzheimer's and she needs to go and get him. If he's there when she calls, tell her not to sleep with him."
