private void xuấtHàngToolStripMenuItem_Click(object sender, EventArgs e)
 {
     frm_XuatHang xuat = new frm_XuatHang();
     xuat.ShowDialog();
 }
        private void xuấtHàngToolStripMenuItem_Click(object sender, EventArgs e)
        {
            frm_XuatHang xuat = new frm_XuatHang();

            xuat.ShowDialog();
        }