public ActionResult QuenMatKhau(QuenMatKhau model)
        {
            if (db.TaiKhoans.Any(x => x.Email == model.Email))
            {
                TaiKhoan t = db.TaiKhoans.Where(x => x.Email == model.Email).FirstOrDefault();
                idrecover = t.Id;
                string code = TaoMaXacNhan.RandomString();
                if (db.MaXacNhans.Any(x => x.UserId == idrecover))
                {
                    MaXacNhan macu = db.MaXacNhans.Where(x => x.UserId == idrecover).First();
                    db.MaXacNhans.Remove(macu);
                }
                MaXacNhan maxn = new MaXacNhan();
                maxn.Code   = code;
                maxn.UserId = idrecover;
                db.MaXacNhans.Add(maxn);
                db.SaveChanges();


                QuenMatKhau mail     = new QuenMatKhau();
                string      bodymail = mail.BodyMail_LayLaiMatKhau(model.Email, code);
                string      ThongBao = mail.Send("Lấy lại mật khẩu", bodymail, model.Email, true, true);
                ViewBag.ThongBao = ThongBao;
            }
            return(RedirectToAction("LayMaXacNhan"));
        }
        public ActionResult LayMaXacNhan(LayMaXacNhan model)
        {
            MaXacNhan maxn = db.MaXacNhans.Find(model.Code);

            if (maxn != null)
            {
                if (maxn.UserId == idrecover)
                {
                    return(RedirectToAction("MatKhauMoi"));
                }
            }
            return(View());
        }