public virtual void sectionTree_BeforeSelect(object sender, TreeViewCancelEventArgs e)
        {
            SectionTreeNode treeNode = e.Node as SectionTreeNode;

            if (treeNode != null)
            {
                e.Cancel = !treeNode.Section.CanActivate;
            }
        }
        public virtual void sectionTree_AfterSelect(object sender, TreeViewEventArgs e)
        {
            SectionTreeNode treeNode = e.Node as SectionTreeNode;

            if (treeNode != null)
            {
                if (ActivateSection(treeNode.Section))
                {
                    headerLabel.Caption = treeNode.Section.Text;
                }
            }
        }