function AddToFavorites() {
    var url = "http://www.productful.com";
    var title = "Free online secure product registration, receipt upload and guarantee tracking!";

    if (window.sidebar) // Firefox   
        window.sidebar.addPanel(title, url, '');
    else if (window.opera && window.print) // Opera   
    {
        var elem = document.createElement('a');
        elem.setAttribute('href', url);
        elem.setAttribute('title', title);
        elem.setAttribute('rel', 'sidebar'); // required to work in opera 7+   
        elem.click();
    }
    else if (document.all) // IE   
        window.external.AddFavorite(url, title);
}