Highlighting Words and Making them Visible.

Hi,

We store a bunch of PDFs in SQL Server, and have implemented a full-text search using a PDF iFilter.  The user enters a keyword or phrase, then gets a list of matching PDFs in a ListBox.  

When the user selects a PDF from the ListBox, we load the PDF document from the database and present it in a RadPdfViewer.

However, I want to highlight the first instance of the word or phrase they searched for.  I've hooked into the PdfViewer's OnDocumentChanged event, and the handler looks like this:

        private void PdfViewerOnDocumentChanged(object sender, DocumentChangedEventArgs documentChangedEventArgs)
        {
            if (SearchText.IsNullOrEmpty())
                return;
            
            DispatcherTimer timer = new DispatcherTimer();
            timer.Interval = TimeSpan.FromMilliseconds(200);
            timer.Tick += (o, args) =>
            {
                var searchResult = this.PdfViewer.Find(SearchText);

                if (!searchResult.Range.IsEmpty)
                {
                    PdfViewer.Document.Selection.Clear();
                    PdfViewer.Select(searchResult.Range);
                    PdfViewer.Document.CaretPosition.MoveToPosition((searchResult.Range.EndPosition));                    
                }
                timer.Stop();
            };
            timer.Start();
        }

This works well most of the time.  However, the area I have on screen for the PdfViewer is smaller than 1 page, and once in a while the word I'm trying to highlight is out of the visible area on the page.  

Is there a method I can use to either always have the highlighted text be visible, or at least detect when the text is near the bottom of the page, and move everything up a bit when that is the case?

Thanks.

Aaron