private void btnDHCPCustomer_ItemClick(object sender, ItemClickEventArgs e) { Waiting.ShowWaitForm(); if (!Class.App.IsFocusForm(typeof(Forms.frmDHCPCustomer), this)) { Forms.frmDHCPCustomer frm = new Forms.frmDHCPCustomer(); frm.MdiParent = this; frm.Show(); } Waiting.CloseWaitForm(); }