1970s High School Yearbook What Is The Name Of The Movie Set In 1970s High School?

What is the name of the movie set in 1970s high school? - 1970s high school yearbook

As the film is called since its installation in 1970, and I think that in the suburbs. It was a group of students who cut class and hold it against the law. In the end, I had this big meeting where parents gathered at the school for a meeting about what to do about all the children in difficulty, but locking the kids parents and teachers in the hall or at school and then go into to destroy the school. Then the film ends with some kids on a bus led to a reform school, and the song "Hey Baby, things are not easier." Thank you.