In Letter of invitation^x, Sponsorship letters^x

I'm sponsoring my sister to go to a College in Canada any suggestions on how to write the sponsorship letter?? Please and Thank you

hi, our class is going to have a fashion show for our events management class, and i need to find sponsors. do you have any sample of sponsorship letter? i have browsed the net, yet i haven't find any. hope you could help me.. thanks a lot.