             
         // create a new renderer
 
-        const columns:IList = grid.columns;
+        const columns:IList = columns;
         if (!columns || (columns.length <= columnIndex))
             return null;
-        const column:GridColumn = grid.columns.getItemAt(columnIndex) as GridColumn;
+        const column:GridColumn = columns.getItemAt(columnIndex) as GridColumn;
         if (!column.visible)
             return null;
         

        const paddingTop:Number = columnHeaderGroup.getStyle("paddingTop");
        const paddingBottom:Number = columnHeaderGroup.getStyle("paddingBottom");
        
        const columns:IList = grid.columns;
        const columnsLength:int = (columns) ? columns.length : 0;
        const lastVisibleColumnIndex:int = grid.getPreviousVisibleColumnIndex(columnsLength);
        const rendererY:Number = paddingTop;

import mx.core.IFactory;
import mx.core.IVisualElement;
import mx.core.mx_internal;
import mx.events.CollectionEvent;
import mx.events.CollectionEventKind;

import spark.components.Grid;
import spark.components.GridColumnHeaderGroup;
