function onDocumentMouseWheel(event) {
    // Only do something if the panorama is loaded and mouse wheel zoom is enabled
    if (!loaded || (config.mouseZoom == 'fullscreenonly' && !fullscreenActive)) {
        return;
    }

    event.preventDefault();

    // Turn off auto-rotation if enabled
    stopAnimation();
    latestInteraction = Date.now();

    if (event.wheelDeltaY) {
        // WebKit
        setHfov(config.hfov - event.wheelDeltaY * 0.05);
        speed.hfov = event.wheelDelta < 0 ? 1 : -1;
    } else if (event.wheelDelta) {
        // Opera / Explorer 9
        setHfov(config.hfov - event.wheelDelta * 0.05);
        speed.hfov = event.wheelDelta < 0 ? 1 : -1;
    } else if (event.detail) {
        // Firefox
        setHfov(config.hfov + event.detail * 1.5);
        speed.hfov = event.detail > 0 ? 1 : -1;
    }
    animateInit();
}