public void addCustomSashFormListener(ICustomSashFormListener listener){
  if (customSashFormListeners == null)   customSashFormListeners=new ArrayList();
  customSashFormListeners.add(listener);
}

public void addCustomSashFormListener ( ICustomSashFormListener listener ) { if ( customSashFormListeners == null ) customSashFormListeners = new ArrayList ( ) ; customSashFormListeners . add ( listener ) ; }
adds a custom sashform listener . this listener will be removed when this control is disposed .
