Leave Letter

When I was in my 12th standard, the college I was studying in, was a very strict one....they usually did not give permission to leave the college during lunch or would call home if we missed college even for a day...But then students always knew how to work around these rules...
Each class had an in-charge, who would be responsible for granting permission to leave the college...We had to write a letter to this person, asking for permission, in case we wanted to get out...They usually maintained a list of who all left college for the day and the reason for that...
My lazy friend did not feel like sitting in the class one day. She wrote a letter to the in-charge on the lines of "...I am not feeling well...I would be highly obliged if you could grant me permission to leave the college..." The in-charge who usually never gives permission to anyone, immediately agreed to let her go...When we saw her list, we knew exactly why...under the "reason for leave", she had clearly written - 'Highly Obliged'.