Listen on file upload - AddItemEvent by ECMA Script (Javascript COM)

Question

I need your help concerning this issue:

I want to upload a document to DocLib. Therefore I call the NewItem2 method

NewItem2(event, referenceURL);

Up to here - no problem. Now the issue:

I want to listen on this event and after the File was uploaded successfully should this:

statusId = SP.UI.Status.addStatus("Upload successful!");
SP.UI.Status.setStatusPriColor(statusId, 'green');

Thanks for all effort!