ต้องการ ทำ Marker clusterer v3 โดยเรียกใช้หมุดจากฐานข้อมูล

<script src="http://www.google.com/jsapi"></script>
    <script type="text/javascript" src="src/data.json"></script>
    <script type="text/javascript">
      var script = '<script type="text/javascript" src="src/markerclusterer';
      if (document.location.search.indexOf('packed') !== -1) {
        script += '_packed';
      }
      if (document.location.search.indexOf('compiled') !== -1) {
        script += '_compiled';
      }
      script += '.js"><' + '/script>';
      document.write(script);

      google.load('maps', '3', {
        other_params: 'sensor=true'
      });
      google.setOnLoadCallback(init);
	 
      function init() {
        var center = new google.maps.LatLng(center_lat, center_lng);
    
        var map = new google.maps.Map(document.getElementById('map'), {
          zoom: poiZoomLevel,
          center: center,
		  mapTypeControl: false,
          mapTypeId: google.maps.MapTypeId.SATELLITE
        });
		
	var markers = [];
	
	<?php $sql2="select * from poi ";
			$query2=mysql_query($sql2);
			while($result2=mysql_fetch_array($query2)){?>
		var latLng = new google.maps.LatLng(<?=$result2["lat"];?>,
               <?=$result2["lng"];?>);
          var marker = new google.maps.Marker({
            position: latLng
          });
          markers.push(marker);
		 <?php }?>
		  
      var markers2 = [];
		  var latLng = new google.maps.LatLng(center_lat,
              center_lng);
          var marker2 = new google.maps.Marker({
            position: latLng
          });
          markers2.push(marker2);
		  var markerCluster2 = new MarkerClusterer(map, markers2);
        
        var markerCluster = new MarkerClusterer(map, markers);
      }
	  
	  
    </script>