public ActionResult EditTeacher(Teacher teacher)
        {
            using (KarateSchoolEntities db = new KarateSchoolEntities())
            {
                db.Entry(teacher).State = System.Data.Entity.EntityState.Modified;
                db.SaveChanges();
            }

            return RedirectToAction("Teach");
        }
        public ActionResult EditEmpl(Employee employee)
        {
            using (KarateSchoolEntities db = new KarateSchoolEntities())
            {
                db.Entry(employee).State = System.Data.Entity.EntityState.Modified;
                db.SaveChanges();
            }

            return RedirectToAction("Empl");
        }
        public ActionResult Edit(Student student)
        {
            using (KarateSchoolEntities db = new KarateSchoolEntities())
            {
                db.Entry(student).State = System.Data.Entity.EntityState.Modified;
                db.SaveChanges();
            }

            return RedirectToAction("Index");
        }