Two old ladies Dolly and Ruby

Two old ladies Dolly and Ruby were talking about their grandchildren.

Dolly said, “Each year I send each of my grandchildren a card with a generous cheque inside. I never hear from them neither receive a thank you message !”

Ruby replies. “I too send them a very generous cheque. I hear from them within a week after they receive it. In fact, they each pay me a personal visit.”

“Wow !, How come?” remarked Dolly.

“Very simple solution, I don’t sign the cheque.”