Embedding button in button

Take a look at my test file if you would, after rolling over the grey area a tween is actioned, at the end a white box appears that I intend to be another button, however going over, pressing, releasing etc the white area the tween begins again, I guess because its effectively patched over the grey area and therefore flash thinks its ok to tween.


How do I script the button to prevent it happening and allow the user to click the white button for further interaction.