Old joke

Courtesy of my old friend Tex, this old guy joke:

Bill and Sam, two elderly friends, met in the park every day to feed the pigeons, watch the squirrels, and discuss world problems.
One day Bill didn't show up. Sam didn't think much about it, figuring maybe he had a cold or something. But after Bill hadn't shown up for a week or so, Sam really got worried. However, since the only time they ever got together was at the park, Sam didn't know where Bill lived, so he was unable to find out what had happened to him. A month passed, and Sam figured he'd seen the last of Bill but, one day, Sam approached the park and, lo and behold, there sat Bill!
Sam was very excited and happy to see him and told him so. Then he said, "For crying out loud, Bill, what in the world happened to you?"
Bill replied, "I've been in jail."
"Jail?" cried Sam. "What in the world for?"
"Well," Bill said, "you know Mary, that cute little blonde waitress at the coffee shop?"
"Yeah," said Sam, "I remember. What about her?"
"Well, one day she filed rape charges against me; and, at 89 years old, I was so proud that, when I got into court, I pled guilty."
"What happened?"
"What happened?" Bill sighed. "The damn judge gave me thirty days for perjury."