google.load("maps","2");
var centrolong = '38.780517385224954';
var centrolat = '-0.4478645324707031';
var address = '<b></b><br><i>Crta. Nacional 340 km. 805</i><br>(03830) Muro de Alcoy - Alicante</a>';
var zoom = 15;
var puntolong = '38.780517385224954';
var puntolat = '-0.4478645324707031';  

    function initialize() {
        if (GBrowserIsCompatible()) {
            map = new GMap2(document.getElementById("map_canvas"));
            map.addControl(new GSmallMapControl());
            map.setCenter(new GLatLng(centrolong, centrolat), zoom);
            map.addControl(new GMapTypeControl());
            map.addControl(new GScaleControl());
            var marker = createMarker (new GLatLng(puntolong, puntolat), address);
        }
    }
    function createMarker(point, address) {
        var marker = new GMarker(point);
        map.addOverlay(marker);
        GEvent.addListener(marker, 'click', function() {
            marker.openInfoWindowHtml(address);
        });
        return marker;
    }
google.setOnLoadCallback(initialize);