public JsonResult GetTeachersByDepartmentId(int departmentId)
        {
            //var teachers = aCourseAssignManager.GetAllTeachers();
            //var teacherList = teachers.Where(a => a.DepartmentId == departmentId).ToList();
            //return Json(teacherList);

            var teacherDetails = aCourseAssignManager.GetTeacherByDepartmentId(departmentId);
            var courseDetails  = aCourseAssignManager.GetCourseByDepartmentId(departmentId);
            Departmentmustafa departmentmustafa = new Departmentmustafa();

            departmentmustafa.Courses  = courseDetails;
            departmentmustafa.Teachers = teacherDetails;
            return(Json(departmentmustafa));
        }
        public JsonResult GetCoursesByDepartmentId(int departmentId)
        {
            List <Course> courses = courseAssignManager.GetCourseByDepartmentId(departmentId);

            return(Json(courses));
        }