private void HighlightSingle(string xpath)
        {
            try
            {
                var hnode = SessionDocument.Current.SelectSingleNode(xpath);
                var node  = SessionDocument.Descendants().Where(x => x.Current == hnode)
                            .FirstOrDefault() as HtmlNodeHierarchy;
                if (node != null)
                {
                    node.Highlight = Brushes.Red;
                }


                hnode = DomDocument.Current.SelectSingleNode(xpath);
                node  = DomDocument.Descendants().Where(x => x.Current == hnode)
                        .FirstOrDefault() as HtmlNodeHierarchy;
                if (node != null)
                {
                    node.Highlight = Brushes.Red;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, ex.GetType().ToString());
            }

            NotifyPropertyChanged("SessionDocument");
            NotifyPropertyChanged("DomDocument");
        }
        private void Highlight(string xpath)
        {
            try
            {
                bool nodefound = false;
                var  sessNodes = SessionDocument.Current.SelectNodes(xpath);
                if (sessNodes != null)
                {
                    foreach (HtmlNodeHierarchy node in SessionDocument.Descendants())
                    {
                        node.Highlight = sessNodes.Contains(node.Current) ? Brushes.Yellow : Brushes.Transparent;
                    }
                    nodefound = true;
                }

                var domNodes = DomDocument.Current.SelectNodes(xpath);
                if (domNodes != null)
                {
                    foreach (HtmlNodeHierarchy node in DomDocument.Descendants())
                    {
                        node.Highlight = domNodes.Contains(node.Current) ? Brushes.Yellow : Brushes.Transparent;
                    }
                    nodefound = true;
                }
                if (!nodefound)
                {
                    MessageBox.Show("null nodes");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, ex.GetType().ToString());
            }

            NotifyPropertyChanged("SessionDocument");
            NotifyPropertyChanged("DomDocument");
        }