processing.js change script source

I need to find a way where I can dynamically change the source of a processing script inside an HTML document.

This is the embedded script which works fine:

<script type='application/processing' src='sketch.txt' id="applet">

  </script>

Now I try to change the source:

$('#applet').attr('src', 'sketch2.txt');

  alert($('#applet').attr('src'));

The alert shows that the source was changed to 'sketch2.txt' but the applet still remains the same. I think I need to refresh the script in some way.

Thank you in advance for any help!