function popUp(url) {
    var width = arguments[1] ? arguments[1] : 455;
    var height = arguments[2] ? arguments[2] : 500;
    var scrollbars = arguments[3] == 'no' ? 'no' : 'yes';
    var popup = window.open(url, 'info','top=20,left=20,scrollbars=' +
scrollbars +
            ',width=' + width + ',height=' + height + ',resizable=yes');
    popup.focus();
    return false;
}