อยากให้ Marker ของ Google map อยู่กึ่งกลางอัตโนมัติครับ

  <script language="JavaScript">
  var map;
  var infowindow;
  function setupMap() {
    var myLatLng = {lat: 14.735042351075299, lng: 99.97695922851562};
    var myOptions = {
      zoom:9,
      center: new google.maps.LatLng(myLatLng),
      mapTypeId: google.maps.MapTypeId.ROADMAP
    };
    map = new google.maps.Map(document.getElementById('map_canvas'),
    myOptions);
    infowindow = new google.maps.InfoWindow();
    selectLocation();
  }
  var makers = [];
  function selectLocation(){
    $.ajax({
      type:"POST",
      url: "location-json.php",
    }).done(function(text){

      var json = $.parseJSON(text);
      for(var i = 0 ;i<json.length;i++){
        var lat = json[i].LCT_LAT;
        var lng = json[i].LCT_LNG;
        var location_name =  json[i].LCT_NAME;
        var latlng = new google.maps.LatLng(lat,lng);
        var makeroption = {
          map:map,
          html:location_name,
          position:latlng };
          var marker = new google.maps.Marker(makeroption);
          google.maps.event.addListener(marker,'click',function(e){
            infowindow.setContent(this.html);
            infowindow.open(map,this);
          });
        }
      });
    };
    </script>