code: public void addListener(GramJobListener listener) {
  	if (listeners == null) listeners = new Vector();
  	listeners.addElement(listener);
      }
docs: Add a listener to the GramJob. The listener will be notified whenever
  the status of the GramJob changes.
  
  @param listener The object that wishes to receive status updates.
  @see org.globus.gram.GramJobListener