Adding Markers on Google Maps

In Source Code(aspx):-

<asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" Runat="Server">

 <meta http-equiv="content-type" content="text/html; charset=utf-8" />

    <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>

</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" Runat="Server">

<div id="map-canvas" style="width: 1000px; height: 600px">

    </div>

  <script type="text/javascript">

      var map;

      var projects = [];

      

      projects.push({ lat: 17.382423, lng: 78.497314 }) //Hyderabad

      projects.push({ lat: 13.04, lng: 80.17 }) //Chennai

      projects.push({ lat: 11.00, lng: 76.15}) //Kerala

      projects.push({ lat: 17.7, lng: 83.3 }) //Visakhapatnam

      function initialize() {

          var mapDiv = document.getElementById('map-canvas');

          map = new google.maps.Map(mapDiv, {

              center: new google.maps.LatLng(17.382423, 78.497314),

              zoom: 6,

              mapTypeId: google.maps.MapTypeId.ROADMAP

          });

          google.maps.event.addListenerOnce(map, 'tilesloaded', addMarkers);

          //map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);

      }

      function addMarkers() {

          var bounds = map.getBounds();

          var southWest = bounds.getSouthWest();

          var northEast = bounds.getNorthEast();

          var lngSpan = northEast.lng() - southWest.lng();

          var latSpan = northEast.lat() - southWest.lat();

          for (var i = 0; i < projects.length; i++) {

              var point = projects[i];

              var latLng = new google.maps.LatLng(point.lat, point.lng);

              var marker = new google.maps.Marker({

                  position: latLng,

                  map: map

              });

              var j = i + 1;

              marker.setTitle(j.toString());

              attachSecretMessage(marker, i);

          }

      }

      google.maps.event.addDomListener(window, 'load', initialize);

      // The  markers show a secret message when clicked

      // but that message is not within the marker's instance data.

      function attachSecretMessage(marker, number) {

          var message = ["Hyderabad","Chennai", “Kerala”,"Visakhapatnam"];

          var infowindow = new google.maps.InfoWindow(

      { content: message[number],

          size: new google.maps.Size(50, 50)

      });

          google.maps.event.addListener(marker, 'click', function () {

              infowindow.open(map, marker);

          });

      }

    </script>

</asp:Content>