public ActionResult Delete(string id, UserViewModel collection)
 {
     try
     {
         _user.delete(id);
         return RedirectToAction("Index");
     }
     catch
     {
         return View();
     }
 }
        public ActionResult Edit(UserViewModel us)
        {
            if (ModelState.IsValid)
                {
                    _user.update(us);

                    return RedirectToAction("Index");
                }

                return View("index");
        }