function popup(url, width, height)
{
    window.open(url, "Static", "top=" + ((window.screen.height - height) / 2) + ", left=" + ((window.screen.width - width) / 2) + ", width=" + width + ", height=" + height + ", buttons=No, scrollbars=Yes, location=No, menubar=No, resizable=Yes, status=No, directories=No, toolbar=No, statusbar=No, copyhistory=No");
}