void dimensionsForm_FormClosed(object sender, FormClosedEventArgs e)
 {
     if (dimensionsForm != null)
     {
         dimensionsForm.Dispose();
         dimensionsForm = null;
     }
 }
 private void buttonDimensions_Click(object sender, EventArgs e)
 {
     if ((dimensionsForm == null) && (modelControl != null))
     {
         dimensionsForm             = new AircraftDimensionsForm(modelControl);
         dimensionsForm.FormClosed += new FormClosedEventHandler(dimensionsForm_FormClosed);
     }
     if (dimensionsForm != null)
     {
         dimensionsForm.Show();
         dimensionsForm.BringToFront();
     }
 }