private void btn_Them_Click(object sender, EventArgs e)
{
frm_themmoihanghoa y = new frm_themmoihanghoa();
y.ShowDialog();
this.Show();
}
private void btn_ThemMoiHangHoa_Click(object sender, EventArgs e)
{
frm_themmoihanghoa t = new frm_themmoihanghoa();
t.ShowDialog();
this.Show();
}