Dear Sir/Ma,
I Wish to indicate my interest to work in your firm as an Office Assistant, I got sight of the vacant position advert on google, and this came at a time when I am in need of a job of this nature. I believe with my experience and knowledge I will become a valuable member of your worthy establishment while I contribute immensely to the growth and development of the organization.
Attached is my CV for your perusal.
Yours faithfully,

Ezebunwo Maryann Chibuzor