private void barButtonItem51_ItemClick(object sender, ItemClickEventArgs e) { barButtonItem51.ButtonStyle = BarButtonStyle.Check; RibonPasif(); if (tsr == null) { tsr = new frm_TaseronTanimlama(); tsr.MdiParent = this; tsr.FormClosed += new FormClosedEventHandler(Tsr_FormClosed); tsr.Show(); } else { tsr.Activate(); } }