Как найти и выделить текст TWebBrowser?

{....}

private
  procedure SearchAndHighlightText(aText: string);

{....}

uses mshtml;

{ .... }


procedure TForm1.SearchAndHighlightText(aText: string);
var
  tr: IHTMLTxtRange; //TextRange Object
begin
  if not WebBrowser1.Busy then
  begin
    tr := ((WebBrowser1.Document as IHTMLDocument2).body as IHTMLBodyElement).createTextRange;
    //Get a body with IHTMLDocument2 Interface and then a TextRang obj. with IHTMLBodyElement Intf.

    while tr.findText(aText, 1, 0) do //while we have result
    begin
      tr.pasteHTML('<span style="background-color: Lime; font-weight: bolder;">' +
        tr.htmlText + '</span>');
      //Set the highlight, now background color will be Lime
      tr.scrollIntoView(True);
      //When IE find a match, we ask to scroll the window... you dont need this...
    end;
  end;
end;

// Example:
procedure TForm1.Button1Click(Sender: TObject);
begin
  SearchAndHighlightText('delphi');
end;