var map;

function createMarker(point, html) {
    var marker = new GMarker(point);
    GEvent.addListener(marker, "click", function() {
        marker.openInfoWindowHtml(html);//"Marker #<b>" + number + "</b>");
    });
    return marker;
}

function createBlueMarker(point, html) {
	var icon = new GIcon();
    icon.image = "/images/blue_marker.png";
    icon.shadow = "/images/blue_marker_shadow.png";
    icon.iconSize = new GSize(20.0, 34.0);
    icon.shadowSize = new GSize(38.0, 34.0);
    icon.iconAnchor = new GPoint(10.0, 17.0);
    icon.infoWindowAnchor = new GPoint(10.0, 17.0);

	//var blueIcon = new GIcon();
	//blueIcon.image = "http://www.visitthecity.co.uk/images/blue_marker.png";
	//blueIcon.iconSize = new GSize(20, 34);
	//blueIcon.iconAnchor = new GPoint(9, 34);
	//blueIcon.infoWindowAnchor = new GPoint(5, 1);

    var marker = new GMarker(point,{icon:icon});
    GEvent.addListener(marker, "click", function() {
        marker.openInfoWindowHtml(html);//"Marker #<b>" + number + "</b>");
    });
    return marker;
}

window.onload = load;
window.onunload = unload;

function load() {
    if (GBrowserIsCompatible()) {
        map = new GMap2(document.getElementById("interactivemap"));
        map.setCenter(new GLatLng(51.5150, -0.0920 ), 13); //reset the center to be a bit south so it includes Croydon
        map.addControl(new GMapTypeControl());
        map.addControl(new GLargeMapControl());
        map.addControl(new GScaleControl());
        //map.addControl(new GOverviewMapControl());

        var bounds = map.getBounds();
        var southWest = bounds.getSouthWest();
        var northEast = bounds.getNorthEast();
        var lngSpan = northEast.lng() - southWest.lng();
        var latSpan = northEast.lat() - southWest.lat();

		for (var i=0; i<type.length; i++) {
            var point = new GLatLng(latitude[i],longitude[i]);
            var address = "";
            if (address1[i]) { address += address1[i] + ' '; }
            if (address2[i]) { address += address2[i] + ' '; }
            if (city[i]) { address += city[i] + ' '; }
            if (postcode[i]) { address += postcode[i]; }

            var markerTxt = "";
            if (id == -1) {
            	markerTxt = "<span id='maplabel'><b>"+name[i]+"</b></span>";
            }
            else {
            	markerTxt = "<span id='maplabel'><a href='/index.php/"+type[i]+"/view/"+id[i]+"' style='color:black;'><b>"+name[i]+"</b></a><br />"+address+"</span>";
            }

			if (is_viewed[i]) {
				var markerObj = new createBlueMarker(point, markerTxt);
				map.addOverlay(markerObj);
            	markerObj.openInfoWindowHtml(markerTxt);
			}
			else {
				var markerObj = new createMarker(point, markerTxt);
				map.addOverlay(markerObj);
			}
        }
    }
}

function unload() {
	GUnload();
}<!-- 0.1999s -->