private void toolStripMenuQuanLyNguoiDung_Click(object sender, EventArgs e)
        {
            FormQLNguoiDung fuser = new FormQLNguoiDung();

            fuser.Show();
        }
 private void toolStripMenuQuanLyNguoiDung_Click(object sender, EventArgs e)
 {
     FormQLNguoiDung fuser = new FormQLNguoiDung();
     fuser.Show();
 }