Trying to copy text from one JFrame to another JFrame

[peahead]

Hi,
Long time no post!

This one has been bugging me for a while and I can't get my head around it.

I have 2 JFrames (JCB and EngineProcess). EngineProcess runs an evaluation routine and outputs the results to a JTextField called 'textArea'. I would like to send the results instead to a JTextField called 'textPositionEvaluationOutput' on my main JFrame (JCB) but nothing happens? Here is my code?

jcb.textPositionEvaluationOutput.setText(textArea.getText());

Here is the code of the evaluation routine if it helps (I did not write this btw)

  private void getEngineOutput(Process engine) {
    try {
      BufferedReader reader =
        new BufferedReader(new InputStreamReader(engine.getInputStream()), 1);
      String lineRead = null;
      while((lineRead = reader.readLine()) != null) {
        textArea.append(lineRead);
        textArea.append("\n");
        textArea.setCaretPosition(textArea.getDocument().getLength() - 0);
	
      }

Any thoughts/pointers anyone?
Thanks