private void ShowSNMPConfigForm()
 {
     if (snmpConfigForm != null)
     {
         snmpConfigForm.Activate();
     }
     else
     {
         snmpConfigForm = new SNMPConfigurationForm(controller);
         snmpConfigForm.Show();
         snmpConfigForm.FormClosed += OnSNMPConfigFormClosed;
     }
 }
 private void OnSNMPConfigFormClosed(object sender, FormClosedEventArgs e)
 {
     snmpConfigForm = null;
 }