private void btHDX_Click(object sender, EventArgs e)
{
FrmHoaDonNhap fr = new FrmHoaDonNhap();
fr.Show();
}
private void btHDN_Click(object sender, EventArgs e)
{
FrmHoaDonNhap fr = new FrmHoaDonNhap();
fr.Sender(nhanvien.MaNV.ToString());
fr.Show();
}