function set myProperty(value:Object) :void
 {
    var oldValue:IPropertyChangeNotifier = _myProperty;
    var newValue:IPropertyChangeNotifier = value;
    
    // Need to ensure to dispatch changes on the new property.
    // Listeners use the source property to determine which object 
    // actually originated the event.
    // In their event handler code, they can tell if an event has been 
    // propagated from deep within the object graph by comparing 
    // event.target and event.source.  If they are equal, then the property
    // change is at the surface of the object.  If they are not equal, the
    // property change is somewhere deeper in the object graph.
    newValue.addEventListener(
                PropertyChangeEvent.PROPERTY_CHANGE, 
                dispatchEvent);
 
    // need to stop listening for events from the old property
    oldValue.removeEventListener(
                PropertyChangeEvent.PROPERTY_CHANGE,
                dispatchEvent);
 
    _myProperty = newValue;
 
    // now notify anyone that is listening
    if (dispatcher.hasEventListener(PropertyChangeEvent.PROPERTY_CHANGE))
    {
         var event:PropertyChangeEvent = 
                         PropertyChangeEvent.createUpdateEvent(
                                                       this,
                                                       "myProperty",
                                                       newValue,
                                                       oldValue);
        dispatchEvent(event);
     }
  }