public IActionResult Find(string song_state)
        {
            if (!LoginUtil.CheckIfLoggedIn(HttpContext))
            {
                return(View(nameof(Index)));
            }

            List <SelectListItem> languageSelectList = _languagesManager.GetSelectListOfLanguages(new StateOfRequest("LangNa"));
            List <SelectListItem> singerSelectList   = _singersManager.GetSelectListOfSingers(new StateOfRequest("SingNa"));

            ViewBag.LanguageList = languageSelectList;
            ViewBag.SingerList   = singerSelectList;
            ViewBag.SongState    = song_state;
            return(View());
        }