public void ReLoadForm()
{
cbTheLoai.DataSource = TheLoaiSach.laydanhsachtheloai();
dtgDanhSachSach.DataSource = sm.LayDanhSachSach();
txtMaSach.Text = sm.GetLastNode().ToString("MS000");
cbNguoiTiepNhan.DataSource = nvm.LayNhanVienThuKho();
cbNamXuatBan.DataSource = DanhSachNamXuatban();
}