public JsonResult GetCoursesTakebByStudent(int studentId)
        {
            IEnumerable <Course> courses = studentResultManager.GetCoursesTakenByaStudentById(studentId);

            return(Json(courses, JsonRequestBehavior.AllowGet));

            //Course aStudentResult = studentResultManager.GetCoursesTakenByaStudentById(studentId).ToList().Find(st => st.Id == studentId);
            //IEnumerable<Course> courses = studentResultManager.GetCoursesTakenByaStudentById(studentId).ToList().FindAll(d =>d.Id == studentId );
            //return Json(courses, JsonRequestBehavior.AllowGet);


            //StudentResult aStudentResult = studentResultManager.GetCoursesTakenByStudentId(studentId).ToList().Find(st => st.Id == studentId);
            //IEnumerable<StudentResult> courses = studentResultManager.GetCoursesTakenByStudentId(studentId).ToList().FindAll(d => d.CourseId == aStudentResult.CourseId);
            //return Json(courses, JsonRequestBehavior.AllowGet);
        }