Birth Control Pills

An elderly woman went into the doctor's office.
When the doctor asked why she was there, she replied :
- I'd like to have some birth control pills.
Taken aback, the doctor thought for a minute and then said :
- Excuse me, Mrs. Smith, but you're 75 years old. What possible use could you have for birth control pills ?
The woman responded :
- They help me sleep better.
The doctor thought some more and continued :
- How in the world do birth control pills help you to sleep ?
The woman said :
- I put them in my granddaughter's orange juice and I sleep better at night.