void inertiaForm_FormClosed(object sender, FormClosedEventArgs e)
 {
     if (inertiaForm != null)
     {
         inertiaForm.Dispose();
         inertiaForm = null;
     }
 }
 private void buttonInertia_Click(object sender, EventArgs e)
 {
     if ((inertiaForm == null) && (modelControl != null))
     {
         inertiaForm = new InertiaForm();
         inertiaForm.ModelControl    = modelControl;
         inertiaForm.InertiaChanged += new EventHandler(inertiaForm_InertiaChanged);
         inertiaForm.FormClosed     += new FormClosedEventHandler(inertiaForm_FormClosed);
     }
     if (inertiaForm != null)
     {
         inertiaForm.Show();
         inertiaForm.BringToFront();
     }
 }