marker clusterer doesn't cluster when zoom - api

Question

i'm trying to learn google api and i want to use marker clusterer. i create a database
from here and do whatever google said. my code is
`
<script src="markerclusterer.js" type="text/javascript"></script>
<script type="text/javascript">
//<![CDATA[
var customIcons = {
restaurant: {
icon: 'images/pin1.png',
shadow: 'http://labs.google.com/ridefinder/images/mm_20_shadow.png'
},
bar: {
icon: 'images/pin2.png',
shadow: 'http://labs.google.com/ridefinder/images/mm_20_shadow.png'
}
};
function initialize() {
var markers = null;
var mcmarkers = [];
var map = new google.maps.Map(document.getElementById("map"), {
center: new google.maps.LatLng(47.6145, -122.3418),
zoom: 12,
mapTypeId: 'satellite'
});
var infoWindow = new google.maps.InfoWindow;
// Change this depending on the name of your PHP file
downloadUrl("phpsqlajax_genxml.php", function(data) {
var xml = data.responseXML;
markers = xml.documentElement.getElementsByTagName("marker");
for (var i = 0; i < markers.length; i++) {
var name = markers[i].getAttribute("name");
var address = markers[i].getAttribute("address");
var type = markers[i].getAttribute("type");
var lat = parseFloat(markers[i].getAttribute("lat"));
var lng = parseFloat(markers[i].getAttribute("lng"))
var point = new google.maps.LatLng(lat, lng);
var html = "<b>" + name + "</b> <br/>" + address;
var icon = customIcons[type] || {};
var marker = new google.maps.Marker({
map: map,
position: point,
icon: icon.icon,
shadow: icon.shadow
});
mcmarkers.push(marker);
var mc = new MarkerClusterer(map, mcmarkers);
bindInfoWindow(marker, map, infoWindow, html);
}
});
}
function bindInfoWindow(marker, map, infoWindow, html) {
google.maps.event.addListener(marker, 'click', function() {
infoWindow.setContent(html);
infoWindow.open(map, marker);
});
}
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('POST', url, true);
request.send(null);
}
function doNothing() {}
//]]>
google.maps.event.addDomListener(window, 'load', initialize);
`
it works well when i open for the first time but when i zoom in or out there was no clusters except max zoom out. i couldn't figure it out. thanks for your help...

Answer 1

var mc = new MarkerClusterer(map, mcmarkers);
This line cannot be placed inside the for loop. but outside after it. I did exactly the same mistake:).