         overlayGroup.layout = new LayoutBase(); // no layout
         overlay.addDisplayObject(overlayGroup);
         
-        // Event handler that dispatch GridEvents
+        // Event handlers that dispatch GridEvents
         
         MouseEventUtil.addDownDragUpListeners(this, 
             chb_mouseDownDragUpHandler, 
             chb_mouseDownDragUpHandler, 
             chb_mouseDownDragUpHandler);
+
         addEventListener(MouseEvent.MOUSE_MOVE, chb_mouseMoveHandler);
-        addEventListener(MouseEvent.ROLL_OUT, chb_mouseRollOutHandler);        
+        addEventListener(MouseEvent.ROLL_OUT, chb_mouseRollOutHandler);
+        addEventListener(MouseEvent.CLICK, chb_clickHandler);
+        addEventListener(MouseEvent.DOUBLE_CLICK, chb_doubleClickHandler);
     }
     
     //--------------------------------------------------------------------------

                {
                    gridEventType = GridEvent.GRID_MOUSE_DOWN;
                    downSeparatorIndex = -1;
                    downColumnIndex = eventSeparatorIndex;
                }
                break;
        }

    //--------------------------------------------------------------------------  
    
    // The down,roll pairs of variables below define column indices.  Only one
    // member of each pair will be not equal to -1 at a time. 
    
    private var rollColumnIndex:int = -1;      // column mouse has rolled into
    private var rollSeparatorIndex:int = -1;   // separator mouse has rolled into
