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