Dear Jones,
Wish you well.
I am writing to thank you for your kindness at night. I enjoyed myself at your birthday party a lot. Your parents and friends were all so kind. The cake and the dishes were all very delicious. The CD was wonderful. Although I didn't know every one at the party, I still had a very good time talking to them.
Thank you again and talk to you soon.
Yours Sincerely,
Harris