function popBM(site) {
    bm_url = this.location.href;
    bm_title = document.title;

    switch (site) {
        case "Facebook":
            url = "http://www.facebook.com/sharer.php?u=__U__";
            break;
        case "Plurk":
            url = "http://www.plurk.com/?qualifier=shares&status=__U__+(__T__)";
            break;
        case "Twitter":
            url = "http://twitter.com/home?status=__T__+__U__";
            break;
        default:
            url = "http://www.facebook.com/sharer.php?u=__U__";
            break;

    }

    url = url.replace('__U__', encodeURIComponent(bm_url));
    url = url.replace('__T__', encodeURIComponent(bm_title));

    window.open(url, '_blank');
}