public void InsertOrUpdate(Respondent respondent)
 {
     if (respondent.Id == default(int))
       {
     // New entity
     context.Respondents.Add(respondent);
       }
       else
       {
     // Existing entity
     context.Entry(respondent).State = EntityState.Modified;
       }
 }
 public ActionResult Edit(Respondent respondent)
 {
     if (ModelState.IsValid)
       {
     respondentRepository.InsertOrUpdate(respondent);
     respondentRepository.Save();
     return RedirectToAction("Index");
       }
       else
       {
     return View();
       }
 }