function a_popup(page) {
    var a_windowStyle = "titlebar,scrollbars=yes,resizable=yes";
    var a_width = 600;
    var a_height = 600;

    a_windowStyle += (",left=" + ((screen.availWidth - a_width) / 2));
    a_windowStyle += (",width=" + a_width);

    a_windowStyle += (",top=" + (((screen.availHeight - a_height) / 2 ) - 30));
    a_windowStyle += (",height=" + a_height);


    var w;
    w = window.open(page, "pop", a_windowStyle);
    w.focus();

    return false;
}