Dear _,
  I am writing the letter for the purpose of extending my sinceregratitude to you for your kindness.
  When I ___, I felt so_ as to ___. But your timely ___ and filled me withenough confidence. Then I was ___ and things ended upsmoothly. But for your help, however, I might have been ___.
  Again,please accept my heartfelt gratitude. I’m eagerly expecting our next meeting.