public ActionResult Add()
        {
            ViewModelStudentAndCities combindeModel = new ViewModelStudentAndCities();

            combindeModel.Cities = logic.DB.Cities.Select(x => x).ToList();
            return(View(combindeModel));
        }
        public ActionResult Add(ViewModelStudentAndCities student)
        {
            Student ConvStudent = new Student();

            if (ModelState.IsValid)
            {
                ConvStudent.Date_of_birth = student.Date_of_birth;
                ConvStudent.Description_  = student.Description_;
                ConvStudent.First_name_   = student.First_name_;
                ConvStudent.Israeli_ID_   = student.Israeli_ID_;
                ConvStudent.Last_name_    = student.Last_name_;
                if (student.SelectedCity.Id == 0)
                {
                    ConvStudent.CityId = null;
                }
                else
                {
                    ConvStudent.CityId = student.SelectedCity.Id;
                }
                logic.DB.Students.Add(ConvStudent);
                logic.DB.SaveChanges();
            }
            return(RedirectToAction("Index"));
        }