private void txtSearch_TextChanged(object sender, EventArgs e)
        {
            if (sByTenSach == true)
            {
                string Tensach = txtSearch.Text;
                var    query   = db.SEARCH_TENSACH(Tensach);
                dgvInfo.DataSource = query.ToList();
                //using (var db = new Model1())
                //{
                //    var query = from d in db.SACHes
                //                where d.TENSACH.Contains(txtSearch.Text)
                //                select d;
                //    dgvInfo.DataSource = query.ToList();
                //}
            }
            else if (sByViTri == true)
            {
                string Vitri = txtSearch.Text;
                var    query = db.SEARCH_VITRI(Vitri);

                //var query = from d in db.Book_Info
                //            where d.VITRI.Contains(txtSearch.Text)
                //            select d;
                dgvInfo.DataSource = query.ToList();

                //using (var db = new Model1())
                //{
                //    var query = from d in db.SACHes
                //                where d.VITRI.Contains(txtSearch.Text)
                //                select d;
                //    dgvInfo.DataSource = query.ToList();
                //}
            }
            //else if (sByMuon == true)
            //{
            //    try
            //    {
            //        using (var db = new Model1())
            //        {
            //            int tmp = int.Parse(txtSearch.Text);
            //            var query = from d in db.SACHes
            //                        where d.DANGDUOCMUON == tmp
            //                        select d;
            //            dgvInfo.DataSource = query.ToList();
            //        }
            //    }
            //    catch
            //    { }
            //}
        }