How do I Identify which clip is playing?

1

… Hi everyone, your help needed again… on my root level I have a pause and play button, I also have 6 mc’s the first ‘p1.mc’ starts on enter frame once it has finished playing it targets the next mc on the root level to run ‘p2.mc’ that in turn on finish runs ‘p3.mc’ and so on… my problem is I want to be able to stop the mc that is playing at the moment the user decides to pause the action…how do I do that?