var map;
var centerLatitude = 54.41893;
var centerLongitude = 0.878906;
var startZoom = 5;
// var centerLatitude = 54.85134;
// var centerLongitude = -3.603634;
// var startZoom = 5;

function addMarker(latitude, longitude, text) {
    var marker = new GMarker(new GLatLng(latitude, longitude));

    GEvent.addListener(marker, 'click',
        function() {
           marker.openInfoWindowHtml(text);
        }
    );

    map.addOverlay(marker);
}

function init() {
    if (GBrowserIsCompatible()) {
        map = new GMap2(document.getElementById("map"));
        map.addControl(new GLargeMapControl());
        map.addControl(new GScaleControl);
        map.setCenter(new GLatLng(centerLatitude, centerLongitude), startZoom);

        for(id in markers) {
           addMarker(markers[id].latitude, markers[id].longitude, markers[id].g_description);
        }
    }
}

window.onload = init;
window.onunload = GUnload;