Dear sir，
I take the liberty to write you in the hope that you might need someone to fill in for you. i feel that i am qualified as an administrator.
I am currently a student at college, i have over a month more to complete before i graduate. my major is business administration.
I have excellent grades in all my subjects. if you wish to look at these information it will be sent to you later.
I have worked at a trading company as a secretary, but i hope to seek more responsible employment.
I am 25 years old and very honest and dependable. if you need someone with my qualifications, please let me know.
Thank you very much for your kind attention.
Sincerely yours