One of your grandparents had completed 100 years.Write a letter congratulating him/her expressing gratitude,praise ,admiration for the way he/she has lived his/her life.

1-7-2012

Hi Granny

I hope you are in best of health. I would like to wish you a very happy 100th birthday. I wish we were together to celebrate this special day in your life. You have been an inspiration for all of us. The life that you have lead and the way you have guided all your children and grand children is commendable. You experience, love and care has been a guiding light for us and we have turned out to be good human beings eventually.

God has showered this long life on you because you have made this life worth living. We all wish that you continue to be our greatest inspiration always. 

Your loving child

Anil