public ActionResult Update(Person person)
 {
     using(var db = new PersonContext())
     {
         db.Persons.Attach(person);
         db.Entry(person).State = EntityState.Modified;
         db.SaveChanges();
         return RedirectToAction("Index");
     }
 }
 public ActionResult Delete(int id)
 {
     using(var db = new PersonContext())
     {
         var p = db.Persons.Find(id);
         db.Entry(p).State = EntityState.Deleted;
         db.SaveChanges();
         return RedirectToAction("Index");
     }
 }