Trouble sleeping

The woman seated herself in the psychiatrists office. “What seems to be the problem?” the doctor asked.

“Well, I, uh,” she stammered. “I think I, uh, might be a nymphomaniac.”

“I see,” he said. “I can help you, but I must advise you that my fee is $80 an hour.”

“That’s not bad,” she replied. “How much for all night?”