Event Java Px

Hi,

I have a Java px for change workflow status event.(from Any status to cancel) I am using pre-syncrhonous event stop on error.  When I cancel my change, it doesn't stop cancelling. Am I missing to throw the error in ActionResult? Can you pls. advise?

Below is my code when there is atleast one affected item on the change.

ActionResult actionResult=new ActionResult(ActionResult.STRING,"Pls. remove the affected items before canceling the change.");

  return new EventActionResult(request, actionResult);

Thanks,

Bhaskar