void tepabm_FormClosed(object sender, FormClosedEventArgs e) { tepabm = null; }
private void checkAllBankMoneyInformationToolStripMenuItem_Click(object sender, EventArgs e) { if (tepabm == null) { tepabm = new TotalEmployeePaymentAndBankMoney(); tepabm.MdiParent = this; tepabm.FormClosed += tepabm_FormClosed; tepabm .Show(); } else { tepabm .Activate(); } }