             columnHeaderBar.horizontalScrollPosition = Number(event.newValue);
     }    
     
-    protected function grid_columnsChangedEventHandler(event:Event):void
-    {
-        if (columnHeaderBar)
-            columnHeaderBar.dataProvider = columns;
-    }    
-    
 }
 }
        
        if (instance == columnHeaderBar)
        {
            columnHeaderBar.dataProvider = null;
            columnHeaderBar.horizontalScrollPosition = 0;
            columnHeaderBar.owner = null;
        }

            const allStyles:Boolean = (styleName == null || styleName == "styleName");
            
            if (allStyles || styleManager.isSizeInvalidatingStyle(styleName))
            {
                if (grid)
                {
                    grid.invalidateSize();
                    grid.clearGridLayoutCache(true);
                }
                if (columnHeaderBar)
                {
                    columnHeaderBar.layout.clearVirtualLayoutCache();
                    columnHeaderBar.invalidateSize();
                }
            }
            
            if (allStyles || (styleName == "alternatingRowColors"))
            {
                initializeGridRowBackground();
                if (grid && grid.layout)
                    grid.layout.clearVirtualLayoutCache();               
            }
            
            if (grid)
                grid.invalidateDisplayList();
            
            if (columnHeaderBar)
                columnHeaderBar.invalidateDisplayList();
        }
    }
    
