To Sir, with Love (1967)

Engineer Mark Thackeray arrives to teach a totally undisciplined class at an East End school. Still hoping for a good engineering job, he's hopeful that he won't be there long. He starts implementing his own brand of classroom discipline: forcing the pupils to treat each other with respect. Inevitably he begins getting involved in the students' personal lives, and must avoid the advances of an amorous student while winning over the class tough. What will he decide when the engineering job comes through?