public void EnrolStudentToCourse(int courseID, int studentID)
        {
            using (ENET_Project_Active_Learning_Group4Entities db = new ENET_Project_Active_Learning_Group4Entities())
            {
                Student_Course_Map map = new Student_Course_Map();
                map.StudentSid = studentID;
                map.CourseSid  = courseID;

                db.Student_Course_Map.Add(map);
                db.SaveChanges();
            }
        }
        public void RemoveStudentFromCourse(int courseID, int studentID)
        {
            using (ENET_Project_Active_Learning_Group4Entities db = new ENET_Project_Active_Learning_Group4Entities())
            {
                Student_Course_Map map = null;;

                foreach (var course in db.Student_Course_Map)
                {
                    if (course.StudentSid == studentID && course.CourseSid == courseID)
                    {
                        map = course;

                        break;
                    }
                }

                if (map != null)
                {
                    db.Student_Course_Map.Remove(map);
                    db.SaveChanges();
                }
            }
        }