anchor.diff:    }
     // add a utfgrid data layer and custom JS events to catch interactivity
     if( options.interactivity ) {
  -    this.addTileInteractivity( tilejson );
  +    this.addTileInteractivity( tilejson, layerID );
     }
     // return the layer and index of this layer in the current stack
     return { layer: layer, layerID: layerID };
  
positive.code:   return utfgridURL + "interactivity=" + interactivity;
  };
  
  google.maps.Map.prototype.addTileInteractivity = function( tilejson ) {
    var map = this;
    wax.g
      .interaction()
      .map(map)
      .tilejson(tilejson)
      .on({
        on: function(o) {
          document.body.style.cursor = 'pointer'
          if (o.e.type == 'click') {
            // if the click is anywhere within the InfoWindow, don't act on it
            if($('.gm-style-iw').parent().find(o.e.target).length > 0) { return false; }
  
negative.code:         }
        },
        off: function(o) {
          // no need to keep setting the option while the mouse
          // is outside any interactive point
          if( interactionOn ) {
            map.setOptions({ draggableCursor: 'url(http://maps.google.com/mapfiles/openhand.cur), move' });
          }
          interactionOn = false;
        }
      });
  };
  