private void ShowDetailsForm()
 {
     if (detailsForm == null)
     {
         detailsForm = new DetailsForm {HostManager = hostManager};
         detailsForm.Closed += detailsForm_Closed; // avoid reshowing a disposed form
         detailsForm.Show();
     }
     else { detailsForm.Activate(); }
 }
 // null out the forms so we know to create a new one.
 private void detailsForm_Closed(object sender, EventArgs e)
 {
     detailsForm = null;
 }