code: function() {
          this.deactivate();
          if(this.dragPan) {
              this.dragPan.destroy();
          }
          this.dragPan = null;
          if (this.pinchZoom) {
              this.pinchZoom.destroy();
              delete this.pinchZoom;
          }
          OpenLayers.Control.prototype.destroy.apply(this,arguments);
      }
docs: Method: destroy
  The destroy method is used to perform any clean up before the control
  is dereferenced.  Typically this is where event listeners are removed
  to prevent memory leaks.