Redwood script to close or change the execution status of a Process queue

Trying to run a Rewwood script to close or change the exection status of a Process quqe. I follow the instrucion in  the Administration Guide, but script is not work. No failure, just not working

Here's my script:

{

  // get the queue

  Queue aQ = jcsSession.getQueueByName("ECC_Queue_TEMP");

  // check to see if the queue is open

  if (aQ.isOpen())

     {

          //hold the queue

          aQ.hold();

          jcsSession.persist();

     }

}

Please review & assist Thanks