var customIcons = {
      MAN: {
        icon: 'vialidad/grupo.png',
        shadow: ''
      },
      COL: {
        icon: 'vialidad/accidente.png',
        shadow: ''
      },
      REP: {
        icon: 'vialidad/obra.png',
        shadow: ''
      },
	  FLU: {
        icon: 'vialidad/fluido.png',
        shadow: ''
      },
      LEN: {
        icon: 'vialidad/lento.png',
        shadow: ''
      },
      PES: {
        icon: 'vialidad/pesado.png',
        shadow: ''
      },
      SEM: {
        icon: 'vialidad/semaforo.png',
        shadow: ''
      },
	  NIE: {
        icon: 'vialidad/niebla.png',
        shadow: ''
      }
    };

    function load() {
      var map = new google.maps.Map(document.getElementById("map"), {
        center: new google.maps.LatLng(19.542624, -96.913744),
        zoom: 13,
        mapTypeId: 'roadmap'
      });
      var infoWindow = new google.maps.InfoWindow;

      downloadUrl("vialidad/gen_vial_xal.php", function(data) {
        var xml = data.responseXML;
        var markers = xml.documentElement.getElementsByTagName("marker");
        for (var i = 0; i < markers.length; i++) {	
	        var name = markers[i].getAttribute("name");
            var address = markers[i].getAttribute("address");
            var fch = markers[i].getAttribute("fch");
            var type = markers[i].getAttribute("type");
            var point = new google.maps.LatLng(
              parseFloat(markers[i].getAttribute("lat")),
              parseFloat(markers[i].getAttribute("lng")));
          var html = "<b>" + address +  "</b><br/>" + fch;
          var icon = customIcons[type] || {};
          var marker = new google.maps.Marker({
            map: map,
            position: point,
            icon: icon.icon,
            shadow: icon.shadow
          });
          bindInfoWindow(marker, map, infoWindow, html);
        }
      });
    }

    function bindInfoWindow(marker, map, infoWindow, html) {
      google.maps.event.addListener(marker, 'click', function() {
        infoWindow.setContent(html);
        infoWindow.open(map, marker);
      });
    }

    function downloadUrl(url, callback) {
      var request = window.ActiveXObject ?
          new ActiveXObject('Microsoft.XMLHTTP') :
          new XMLHttpRequest;

      request.onreadystatechange = function() {
        if (request.readyState == 4) {
          request.onreadystatechange = doNothing;
          callback(request, request.status);
        }
      };

      request.open('GET', url, true);
      request.send(null);
    }

    function doNothing() {}