private void btnSua_Click(object sender, EventArgs e)
{
FrmThongTinHangHoa frm = new FrmThongTinHangHoa(eHangHoa);
frm.ShowDialog();
}
private void btnNhapHang_Click(object sender, EventArgs e)
{
FrmThongTinHangHoa frm = new FrmThongTinHangHoa(null);
frm.ShowDialog();
}