TV program sponsorship letters

Hi,

I am desperately in need of your assistance. I have been asked to send a TV programme sponsorship letter to a potential sponsor and i dont have the faintest clue how to write one. I have searched numerous sites, your site is the closest to finding assistance. Can you please give mesome examples of letters on how to write one or where to search for writing examples for this type of letter.

Many thanks,

Fynegirl.