private void khoHàngToolStripMenuItem_Click(object sender, EventArgs e)
 {
     FormSanPham frm = new FormSanPham();
     frm.ShowDialog();
 }
        private void khoHàngToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FormSanPham frm = new FormSanPham();

            frm.ShowDialog();
        }