How can I get a famous celebrity to act in an independent film?

I am a filmmaker. I am not famous or rich and I have yet to make a film debut yet, But I have a pretty good script written. If I wanted to, how would I get a famous actor/actress to do a film?|||I suggest contacting their manager to see, hope this helps- its pretty hard i would think to get someone famous.|||There are very few good actors who do independent films but willem dafoe does alot of independent films if they like it they will do it. By the way what is it about?