After completing work on a patient, the dentist begged him for some help.

"Could you help me out?" the dentist pleaded. "Could you let out a few loud, bloodcurdling screams?"

"Why, doc?" the patient asked. "It wasn't all that bad this time."

"The waiting room is packed with people right now," the dentist explained, "and I don't want to miss the four o'clock game!"