public void DLTrenTungTrang_KhachHang()
{
dgvKhachHang.DataSource = bus_khachhang.PhanTrang_KhachHang(currentPageKhachHang);
BuocDlVaoCacDieuKhien_KhachHang();
txtTrangKH.Text = currentPageKhachHang.ToString();
lblTongTrangKH.Text = "/" + bus_khachhang.totalPage;
}