function initialize() {
  
  var myOptions = {
   scrollwheel: false,
   zoom: 9,
   mapTypeId: google.maps.MapTypeId.TERRAIN
  };
  map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
  var stylerif = [{
        url: 'http://www.rifuginrete.com/images/rifn1.png',
        height: 35,
        width: 40,
        anchor: [12, 0],
        textSize: 16
      }, {
        url: 'http://www.rifuginrete.com/images/rifn2.png',
         height: 44,
        width: 50,
        anchor: [15, 0],
        textSize: 19
      }, {
        url: 'http://www.rifuginrete.com/images/rifn3.png',
        height: 44,
        width: 50,
        anchor: [19, 8],
        textSize: 19
  }];
  var OptionsBox = {
    disableAutoPan: false,
    maxWidth: 0,
    pixelOffset: new google.maps.Size(-125, -80),
    zIndex: null,
    closeBoxMargin: '-5px -5px 0px 0px',
    closeBoxURL: 'http://www.rifuginrete.com/images/close3.png',
    infoBoxClearance: new google.maps.Size(1, 1),
    isHidden: false,
    pane: 'floatPane',
    enableEventPropagation: true,
  };
  
  markerClusterer = new MarkerClusterer(map, [], {
      maxZoom: 13,
      gridSize: 20,
      styles: stylerif
    });

  var sentiero_coordinate = [];
  var sentiero = null;
}

function visualize(params) {

  // if (sentiero_coordinate) {sentiero.setMap(null);}
 var OptionsBox = {
    disableAutoPan: false,
    maxWidth: 0,
    pixelOffset: new google.maps.Size(-125, -80),
    zIndex: null,
    closeBoxMargin: '-5px -5px 0px 0px',
    closeBoxURL: 'http://www.rifuginrete.com/images/close3.png',
    infoBoxClearance: new google.maps.Size(1, 1),
    isHidden: false,
    pane: 'floatPane',
    enableEventPropagation: true,
    };

 var OptionsBox_DM = {
    disableAutoPan: false,
    maxWidth: 0,
    pixelOffset: new google.maps.Size(-150, -100),
    zIndex: null,
    closeBoxMargin: '-5px -5px -10px -10px',
    closeBoxURL: 'http://www.rifuginrete.com/images/close3.png',
    infoBoxClearance: new google.maps.Size(1, 1),
    isHidden: false,
    pane: 'floatPane',
    enableEventPropagation: true,
    };

  markerClusterer.clearMarkers();


  var randomPoint;
  var markers = [];
  var markerBounds = new google.maps.LatLngBounds();
  var el = document.getElementById("maps_title");
  var des = document.getElementById("maps_descrizione");

  if (params !='WC' && params !="IU"){