how do i get a work authorization form for a repair?

My MacBook Pro has some structural damage and I am trying to get it repaired. I have a reservation at the Genius Bar set for Wednesday. On the website however, it says that if a repair is needed, then I need a work authorization form and to bring it with me. I was wondering how I get one of these forms. Do I print it off from their website? I don't know. Please help!!