An old man was enjoying his hundredth birthday party when a  reporter approached him and asked, "Sir, what is the secret of your longevity?"

The old man thought for a moment, then replied, "Well, young  man, every evening at 7 PM I have a glass of Prune Juice. They say it's good for the heart, you know."

"That's it?" asked the reporter.

"That," the old man said, "and canceling my voyage on the  Titanic."