void GetUrl()
        {
            if (log == null)
            {
                return;
            }
            string   url = log.Url;
            TreeNode n   = treeViewMain.Find(url);

            if (n != null)
            {
                if (treeViewMain.SelectedNode == n)
                {
                    return;
                }
                treeViewMain.SelectedNode = n;
                ILogItem d = n.Tag as ILogItem;
                toolStripLabelSize.Text    = "Length = " + d.GetLength();
                toolStripLabelSize.Visible = true;
            }
            else
            {
                toolStripLabelSize.Visible = false;
            }
        }
        void SetUrl()
        {
            TreeNode n = treeViewMain.SelectedNode;

            if (n == current)
            {
                return;
            }
            current = n;
            changeNode(n);
            if (n == null)
            {
                return;
            }
            if (log == null)
            {
                return;
            }
            if (n.Tag is ILogItem)
            {
                ILogItem d   = n.Tag as ILogItem;
                string   uid = d.GetUrl();
                try
                {
                    log.Url = uid;
                    toolStripLabelSize.Text    = "Length = " + d.GetLength();
                    toolStripLabelSize.Visible = true;
                }
                catch (Exception exception)
                {
                    exception.ShowError();
                }
                return;
            }
            toolStripLabelSize.Visible = false;
        }