public bool AddSupplementCancel(long subjectId, int day, int order)
        {
            ISubject subject = SchoolService.repo.Subject.Find(subjectId);
            ITeachingHour hour = SchoolService.repo.TeachingHour.FindByDayOrder(day, order);
            ISupplement supplement = new Supplement(true, DateTime.Now, hour, subject.Schedule);

            SchoolService.repo.Supplement.Update(supplement);

            return true;
        }
        public bool AddSupplement(long subjectId, int day, int order, long teacherId)
        {
            ISubject subject = SchoolService.repo.Subject.Find(subjectId);
            ITeachingHour hour = SchoolService.repo.TeachingHour.FindByDayOrder(day, order);
            IPerson teacher = SchoolService.repo.Person.Find(teacherId);
            ISupplement supplement = new Supplement(false, DateTime.Now, hour, subject.Schedule, teacher);

            SchoolService.repo.Supplement.Update(supplement);

            return true;
        }