Google Maps JS

gistfile1.js

function buttonHandler(layername, type) {
    var layer = layers[layername];
    var kml = loadKML(layer);
    if ( document.getElementById(layername).checked === true ) {
        //show loading spinner
        $('#loadingGif').removeClass('invisible');

        //load KML and draw to map
        kml.setMap(map);
        redrawRoutes(kml);

        //hide loading spinner
        google.maps.event.addListener(kml, 'metadata_changed', function() {
            $('#loadingGif').addClass('invisible');
        });

        pageTracker._trackEvent(layername, 'Load Layer');

    } else {
        kml.setMap(null);
    }
}