Dear my fri,
  It is great to have you in my life for helping me both in my study and in my personal affairs. I have to say thank you  the bottom of my mind. You were so nice to me and so helpful that I could not even overcome any of the difficulties that I have encountered without the assistance  you. Please accept my sincere appreciation for what you have done and I will definitely cherish the friship we have.
  Wish you all the best.
  Regards,