         if (_layout)
         {
             _layout.target = null;
-            _layout.removeEventListener("propertyChange", redispatchLayoutEvent);
+            _layout.removeEventListener(PropertyChangeEvent.PROPERTY_CHANGE, redispatchLayoutEvent);
         }
         _layout = value; 
         if (_layout)
         {
             _layout.target = this;
-            _layout.addEventListener("propertyChange", redispatchLayoutEvent);
+            _layout.addEventListener(PropertyChangeEvent.PROPERTY_CHANGE, redispatchLayoutEvent);
         }
 
         invalidateSize();

import mx.collections.ICollectionView;
import mx.collections.IList;
import mx.collections.ListCollectionView;
import spark.components.ResizeMode;
import mx.controls.Label;
import mx.core.IFactory;
import mx.core.ILayoutElement;
import spark.core.IViewport;
import mx.core.IVisualElement;
import mx.core.UIComponent;
import mx.core.mx_internal;

    [Inspectable(category="General")]    

    /**
     *  @copy spark.core.IViewport#contentHeight
     *  
     *  @langversion 3.0
     *  @playerversion Flash 10
