Json demo

The Demo Services/Simple works well.
But the exact same Code in my Application compiled fine.
At runtime i get an Error in the browser and it dont work.

Part of the code:

procedure TForm1.WebHttpRequest1Response(Sender: TObject; AResponse: string);
var
  js: TJSON;
  ja: TJSONArray;
  jo: TJSONObject;
  i: integer;
begin
  js := TJSON.Create;

  try
    ja := TJSONArray(js.Parse(AResponse));

    ShowMessage('Retrieved items:' +inttostr(ja.Count));


The error message is :

ERROR
TypeError: ja.GetItem$1 is not a function

Are you sure the returned JSON is an array?

Yes it was a Array, but i found ther was a small Syntaxerror in the JSON-Answer.
That was wrong.

Thanks.