public ActionResult Create([DataSourceRequest] DataSourceRequest request, CourseGridViewModel course)
        {
            if ((course != null) && (ModelState.IsValid))
            {
                var newCourse = new Course()
                {
                    Title = course.Title,
                    Lecturer = course.Lecturer,
                    Description = course.Description,
                    IsActive = course.IsActive
                };

                this.Data.Courses.Add(newCourse);
                this.Data.SaveChanges();
                course.Certificates = new List<string>();
                course.Id = newCourse.Id;
            }

            return Json(new[] { course }.ToDataSourceResult(request, ModelState));
        }
        public ActionResult Update([DataSourceRequest] DataSourceRequest request, CourseGridViewModel course)
        {
            if (course != null && ModelState.IsValid)
            {
                var target = this.Data.Courses.All(new string[] { "Certificates"}).FirstOrDefault(c => c.Id == course.Id);
                if (target != null)
                {
                    target.Title = course.Title;
                    target.Description = course.Description;
                    target.Lecturer = course.Lecturer;

                    course.Certificates = target.Certificates.Select(c => c.Title).ToList();
                    this.Data.SaveChanges();
                }
            }

            return Json(new[] { course }.ToDataSourceResult(request, ModelState));
        }