private void bbtKhachCTT_ItemClick(object sender, ItemClickEventArgs e)
        {
            Form frm = this.Kiemtratontai(typeof(HoadonKCTT));

            if (frm != null)
            {
                frm.Activate();
            }
            else
            {
                HoadonKCTT kctt = new HoadonKCTT();
                kctt.MdiParent = this;
                //dmk.StartPosition = FormStartPosition.CenterParent;
                kctt.WindowState = FormWindowState.Maximized;
                kctt.Show();
            }
        }
        private void kháchCóThôngTinToolStripMenuItem_Click(object sender, EventArgs e)
        {
            HoadonKCTT hdkctt = new HoadonKCTT();

            hdkctt.Show();
        }