Grandma loved her grandchildren and always sent them generous checks for Christmas. She had noticed, though, that in the last couple of years, the grandchildren were not sending her thank you notes.

This year things were different, however. One day, she was telling a friend how wonderful things were now.

"The children came over in person to thank me," grandma told a friend triumphantly.

"How wonderful!" the friend exclaimed. "What do you think caused the change in behavior?"

"Oh, that's easy," grandma replied. "This year I didn't sign the checks."