Where can I find hip hop dance classes for teenagers 15-up in San Francisco?

I have a couple of teenage girls that are looking for an outlet. Dancing is what they love, so if I could find dance classes or a hip hop dance teacher that will teach my girls twice a week it would really give them hope. They are really good kids they just need something they like/love to do that will pull them away from the streets. My goal is to keep them away from drugs, sex, and violence, and by starting a positive group that they can be a part of would be a great accomplishment.Where can I find hip hop dance classes for teenagers 15-up in San Francisco?
find a reputable dance company by looking through local community parenting magazines.....dance companies place ads in the papers for their upcoming classes.....You can try word of mouth and the internet, but going through newspaper ads is really the best way