英文信件格式的問題

Dear Principal,

My name is________. I am in_________ (Your class and class no.).
(Content) _______________________________________________________

Yours sincerely,
_____________

2007-01-05 17:34:53 補充：
Do not say ' How are you?' at the begining of the letter as this is only for friends and relatives, not for principal, teachers, etc. If you write ' How are you?', the principal may think you are not respecting him/her.This is what my English teacher told me.

dear.........., ...................
How are you?.........................
.........................................................................................................................................................................................................
.............................................................................................................................................................................................................................................................................................................................................................................................
yours,
..............

2007-01-05 17:26:53 補充：
just like this.

http://www.nkstars.org/blog/archives/sen/000309.html
此網中有詳細的解釋!!*