Help me find a sponsor to pay for prom?

My dad recently lost his job, and no will hire me. I haven't been to any school sponsored event since the start of high school because my parents wouldn't allow it. They're allowing me to go to prom if I can figure out how to pay for it.. How can I find a sponsor (in the LA area) to help me pay for my dress, hair and makeup, and ticket? Any other fundraising ideas? Prom is about 3 weeks away...