What do I need to add & where - to make my markers popup the info window, using my var locations txt?
    <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script>
    <script>
var map;
var brooklyn = new google.maps.LatLng(48.1391265, 11.580186300000037);
var MY_MAPTYPE_ID = 'custom_style';
function initialize() {
  var mapOptions = {
    zoom: 2,
    center: new google.maps.LatLng(48.1391265, 11.580186300000037),
    disableDefaultUI: true,
    mapTypeControl: true,
    mapTypeControlOptions: {
      style: google.maps.MapTypeControlStyle.DROPDOWN_MENU
    },
    zoomControl: true,
    panControl: true,
    mapTypeId: google.maps.MapTypeId.ROADMAP,
        styles: [ { stylers: [ { hue: "#098AAD" } ] } ]
  }
  var map = new google.maps.Map(document.getElementById('map-canvas'),
                                mapOptions);
  setMarkers(map, locations);
}
var locations = [
  ['Plano TX', 33.01984, -96.69889, 13],
  ['Hemel Hempstead UK', 51.75324, -0.44863, 12],
  ['Dubai', 25.27114, 55.30748, 11],
  ['San Francisco CA', 37.77493, -122.41942, 10],
  ['Chicago IL', 41.87811, -87.62980, 9],
  ['New York NY', 40.71435, -74.00597, 8],
  ['Troy MI', 42.60559, -83.14993, 7],
  ['Santa Monica CA', 34.01945, -118.49119, 6],
  ['St Peters MO', 38.78747, -90.62989, 5],
  ['Pittsford NY', 43.09062, -77.51500, 4],
  ['Las Vegas NV', 36.11465, -115.17282, 3],
  ['Haidian Beijing', 39.95991, 116.29805, 2],
  ['New Delhi', 28.63531, 77.22496, 1]
];
function setMarkers(map, locations) {
  var image = {
    url: 'images/marker-rmg.png',
    size: new google.maps.Size(32, 32),
    origin: new google.maps.Point(0,0),
    anchor: new google.maps.Point(16, 32)
  };
  var shape = {
      coord: [1, 1, 1, 20, 18, 20, 18 , 1],
      type: 'poly'
  };
  for (var i = 0; i < locations.length; i++) {
    var location = locations[i];
    var myLatLng = new google.maps.LatLng(location[1], location[2]);
    var marker = new google.maps.Marker({
        position: myLatLng,
        map: map,
        icon: image,
        shape: shape,
        title: location[0],
        zIndex: location[3]
    });
  }
}
google.maps.event.addDomListener(window, 'load', initialize);
    </script>
    <div id="map-canvas" style="height: 300px;"></div>
 
     
    