What is this movie called? kids living on the streets?

I recently saw a movie about a bunch of kids living on the streets, doing drugs and prostituting. the main character is a blonde girl who ran away from home. she makes her way through different cities. and she likes a black kid. but she leaves him. and she ends up going back home. but I think at the end she runs away again?
it's kind of an older movie.
please help!