private void button11_Click(object sender, EventArgs e)
        {
            //Hide sub menu filemaintenance
            panelFileMaintenanceSub.Visible = false;

            //controls
            foreach (Form form in Application.OpenForms)
            {
                if (form.GetType() == typeof(Banks))
                {
                    form.Activate();
                    return;
                }
            }

            Banks frm = new Banks();

            frm.Show();
            frm.MdiParent = this;
            frm.cleartxtField();
        }