A man phones a mental hospital and asks the receptionist...
A man phones a mental hospital and asks the receptionist if there is anybody in room 27. She goes and checks, and comesback to the phone, telling him No, the room is empty. "Good," says the man. "That means I must have really escaped."

1stPerson: "Do you know anything about...
1st Person: "Do you know anything about this fax-machine?"
2nd Person:"A little. Whats wrong?"
1st Person: "Well, I sent a fax, and the recipient called back to say all she received was a cover-sheet and a blank page. I tried it again, and the same thing happened."
2nd Person: "How did you load the sheet?"
1st Person: "Its a pretty sensitive memo, and I didn't want anyone else to read it by accident, so I folded it so only the recipient could open it and read it."