var win;

function popup(url, width, height) {
  if (win && !win.closed) win.close();
  if (url.search(new RegExp("\.(jpg|gif|png)$", "i")) != -1)
    url = "../_popup-img.php?url=" + url;
  win = window.open(url, "popup", "width=" + (width + 32) +",height=" + (height + 16) + ",scrollbars=yes");
}