private void OnTimerTick(object sender, EventArgs e)
        {
            if (htmldoc == null)
            {
                return;
            }
            if (htmldoc.State != HtmlDocumentState.Complete)
            {
                return;
            }

            ToggleBold.IsChecked          = htmldoc.IsBold();
            ToggleItalic.IsChecked        = htmldoc.IsItalic();
            ToggleUnderline.IsChecked     = htmldoc.IsUnderline();
            ToggleSubscript.IsChecked     = htmldoc.IsSubscript();
            ToggleSuperscript.IsChecked   = htmldoc.IsSuperscript();
            ToggleBulletedList.IsChecked  = htmldoc.IsBulletsList();
            ToggleNumberedList.IsChecked  = htmldoc.IsNumberedList();
            ToggleJustifyLeft.IsChecked   = htmldoc.IsJustifyLeft();
            ToggleJustifyRight.IsChecked  = htmldoc.IsJustifyRight();
            ToggleJustifyCenter.IsChecked = htmldoc.IsJustifyCenter();
            ToggleJustifyFull.IsChecked   = htmldoc.IsJustifyFull();

            FontFamilyList.SelectedItem = htmldoc.GetFontFamily();
            FontSizeList.SelectedItem   = htmldoc.GetFontSize();
        }