Проверка текста в WebBrowser

[nibufep]

Добрый день!

 function WB_GetHTMLCode(WebBrowser: TWebBrowser; ACode: TStrings): Boolean;
 var
   ps: IPersistStreamInit;
   ss: TStringStream;
   sa: IStream;
   s: string;
 begin
   ps := WebBrowser.Document as IPersistStreamInit;
   s := '';
   ss := TStringStream.Create(s);
   try
     sa := TStreamAdapter.Create(ss, soReference) as IStream;
     Result := Succeeded(ps.Save(sa, True));
     if Result then ACode.Add(ss.Datastring);
   finally
     ss.Free;
   end;
 end;

HTMLCode:=tstringlist.Create;
WebBrowser1.Navigate('http://');
WB_GetHTMLCode(Webbrowser1, HTMLCode);

if pos('',HTMLCode.Text)<>0 then begin
///
end;

HTMLCode.Free;

Получаю ошибку Access violation at address 0070FE5C in module 'Project.exe'. Read of address 00000000

Мб можно как то проще проверить? Или из-за чего возникает эта ошибка?

[Stilet]

Я так понимаю трассировку конечно же не делал?

[Shouldercannon]

function WB_GetHTMLCode(WebBrowser: TWebBrowser): String;
var
  PS: IPersistStreamInit;
  SS: TStringStream;
  SA: IStream;
  s: String;
begin
  PS := WebBrowser.Document as IPersistStreamInit;

  if Assigned(PS) then
  begin
    s := '';

    try
      SS := TStringStream.Create(s);
      SA := TStreamAdapter.Create(SS, soReference) as IStream;
      try
        PS.Save(SA, False);
        Result := SS.Datastring;
      except
      end;
    finally
      FreeAndNil(SS);
    end;
  end;
end;