private void barButton_License_ItemClick(object sender, ItemClickEventArgs e)
 {
     try
     {
         if (FormCompanyLicense != null)
         {
             FormCompanyLicense.Visible = true;
             FormCompanyLicense.Activate();
         }
         else
         {
             FormCompanyLicense         = new CompanyLicense_Form();
             FormCompanyLicense.Closed += FormCompanyLicense_Closed;
             AddOwnedForm(FormCompanyLicense);
             FormCompanyLicense.MdiParent = this;
             FormCompanyLicense.Show();
         }
     }
     catch (Exception ex)
     {
         LogError.WriteLogError("ShowFormMain", ex);
         MessageBox.Show("Lỗi show form");
     }
 }
 private void FormCompanyLicense_Closed(object sender, EventArgs e)
 {
     FormCompanyLicense.Dispose();
     FormCompanyLicense = null;
 }