anchor.diff:      }, <%= @counter %> * 180);
         <% end %>
       <% end %>
  +  }
  +
  +  function setActive(current) {
  +    markerList.forEach(function(marker){
  +      marker.setIcon(iconInactive);
  +      if (marker.getZIndex() == current) marker.setIcon(iconActive);
  +    });
     }
   
     google.maps.event.addDomListener(window, 'load', initialize);
  
positive.code: </script>
  <script type="text/javascript">
    var markerList;
    function initialize() {
      markerList = new google.maps.MVCArray();
      var styles = [{"featureType":"landscape","stylers":[{"saturation":-100},{"lightness":65},{"visibility":"on"}]},{"featureType":"poi","stylers":[{"saturation":-100},{"lightness":51},{"visibility":"simplified"}]},{"featureType":"road.highway","stylers":[{"saturation":-100},{"visibility":"simplified"}]},{"featureType":"road.arterial","stylers":[{"saturation":-100},{"lightness":30},{"visibility":"on"}]},{"featureType":"road.local","stylers":[{"saturation":-100},{"lightness":40},{"visibility":"on"}]},{"featureType":"transit","stylers":[{"saturation":-100},{"visibility":"simplified"}]},{"featureType":"administrative.province","stylers":[{"visibility":"off"}]},{"featureType":"water","elementType":"labels","stylers":[{"visibility":"on"},{"lightness":-25},{"saturation":-100}]},{"featureType":"water","elementType":"geometry","stylers":[{"hue":"#ffff00"},{"lightness":-25},{"saturation":-97}]}];
  
negative.code:   $('.flexslider').flexslider({
      animation: "slide",
      animationLoop: true,
      controlNav: false,
      after : function(slider){
        setActive(slider.currentSlide);
      },
    });
  });
  </script>
  