This document provides instructions for writing an informal letter to a friend who has been caught smoking, advising them to stop. It outlines the format, including adding address details in the top left corner and beginning the letter with "Dear [Friend's Name]". The body of the letter should use the first paragraph to ask about the friend's life, and the second paragraph to advise them about the dangers of smoking and reasons to quit, referring them to included web resources. The letter should be signed off with "I hope to hear from you soon" and the writer's name.