public IHttpActionResult GetAddNewEnrollment(int courseId)
        {
            if (courseId == null || courseId == 0)
            {
                return StatusCode(HttpStatusCode.NotFound);
            }
            var statucosde = HttpStatusCode.NotModified;
            using (StoreContext context = new StoreContext())
            {
                if (User.Identity.IsAuthenticated)
                {
                    Student currentStudent = context.Students.Where(q => q.UserName == User.Identity.Name).FirstOrDefault();
                    if (currentStudent != null)
                    {
                        if (context.Enrollments.Where(q => q.StudentId == currentStudent.StudentId && q.CourseId == courseId).FirstOrDefault() == null)
                        {
                            context.Enrollments.Add(new Enrollment { CourseId = courseId, StudentId = currentStudent.StudentId });
                            context.SaveChanges();
                            statucosde = HttpStatusCode.OK;
                        }
                    }
                }
            }

            return StatusCode(statucosde);
        }