Menggunakan SQL di Google Maps Javascript

<?php
$username="username anda";
$password="password anda";
$database="nama database yang ingin anda pakai";
?>

<?php  
require("phpsqlajax_dbinfo.php"); 
// Start XML file, create parent node

$dom = new DOMDocument("1.0");
$node = $dom->createElement("markers");
$parnode = $dom->appendChild($node); 
// Opens a connection to a MySQL server

$connection=mysql_connect (localhost, $username, $password);
if (!$connection) {  die('Not connected : ' . mysql_error());} 
// Set the active MySQL database

$db_selected = mysql_select_db($database, $connection);
if (!$db_selected) {
  die ('Can\'t use db : ' . mysql_error());
} 
// Select all the rows in the markers table

$query = "SELECT * FROM markers WHERE 1";
$result = mysql_query($query);
if (!$result) {  
  die('Invalid query: ' . mysql_error());
} 

header("Content-type: text/xml"); 
// Iterate through the rows, adding XML nodes for each
while ($row = @mysql_fetch_assoc($result)){  
  // ADD TO XML DOCUMENT NODE  
  $node = $dom->createElement("marker");  
  $newnode = $parnode->appendChild($node);   
  $newnode->setAttribute("name",$row['name']);
  $newnode->setAttribute("address", $row['address']);  
  $newnode->setAttribute("lat", $row['lat']);  
  $newnode->setAttribute("lng", $row['lng']);  
  $newnode->setAttribute("type", $row['type']);
} 

echo $dom->saveXML();
?>

    function initialize() {
        var myposition=new google.maps.LatLng(-6.231518,106.866674)
        var mapOptions = {
          center: myposition,
          zoom: 16,
          mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        var map = new google.maps.Map(document.getElementById("map_canvas"),
            mapOptions);
        downloadUrl("phpsqlajax_genxml.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 point=new google.maps.LatLng(markers[i].getAttribute("lat"),markers[i].getAttribute("lng"));
          var marker = new google.maps.Marker({
            map: map,
            position: point,
            title: name,
            icon: 'link icon, bisa dihilangkan jika ingin default'
          });
        
        }
      });
      }
    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() {}