public ActionResult Create(Trener trener)
        {
            if (ModelState.IsValid)
            {
                db.Treners.Add(trener);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            return View(trener);
        }
 public ActionResult Edit(Trener trener)
 {
     if (ModelState.IsValid)
     {
         db.Entry(trener).State = EntityState.Modified;
         db.SaveChanges();
         return RedirectToAction("Index");
     }
     return View(trener);
 }