code: function() {
  
          this._removeZoomBar();
  
          this.map.events.un({
              "changebaselayer": this.redraw,
              "updatesize": this.redraw,
              scope: this
          });
  
          OpenLayers.Control.PanZoom.prototype.destroy.apply(this, arguments);
  
          delete this.mouseDragStart;
          delete this.zoomStart;
      }
docs: Constructor: OpenLayers.Control.PanZoomBar
   
  APIMethod: destroy