How To Write A Leave Letter To My Boss For Cousins Daughter Birthday?

I beg to state that my younger brother have been got son for 4.06.2009. On this occasions have a party programme held on 25.06.2009. So I want leave for three days to attend this party. Kindly sanction my leave from 25.06.2009 to 28.06.2009.
Your Sincerely
B L Y

Respected sir
I wish you inform that I need a --- days leave from ----to ---
for Cousins Daughter Birthday
So please grant me a leave & I will be rejoining on ------
Hope you will do.