public ActionResult Create(Staff staff)
        {
            if (ModelState.IsValid)
            {
                _db.Staff.Add(staff);
                _db.SaveChanges();
                return RedirectToAction("Index");
            }

            return View(staff);
        }
 public ActionResult Edit(Staff staff)
 {
     if (ModelState.IsValid)
     {
         _db.Entry(staff).State = EntityState.Modified;
         _db.SaveChanges();
         return RedirectToAction("Index");
     }
     return View(staff);
 }