dear madam
my board exam is coming and it is in this light that
i would like to avail all my leave credits (15 days w/pay) and would like to request for an additional of 45 days' leave of absence(w/o pay) for my study review.
my prospect proposed leave will starts from aug 5 to october 25 (60 days).
i hope that this request will merit a favorable response from your office.
thank you.
sincerely obediently yours
-me
Note: I take it that your office is used to receiving letters in writing without capital letters.