function open_nletter(regonly) {
  var args = "";
  var d = document;		
  var n = Math.floor(4532763984781*Math.random());
  if (regonly > 0) 
      args = "register_only=1&";
  var u="https://ssl.obop.com.pl/sbin/nletter/register?" + args;
  var p=u; //+'pp_url='+escape(d.location); if(d.referrer) p+='&pp_ref='+escape(d.referrer);
  window.open(p,'newsletter_w','resizable=no,menubar=no,scrollbars=yes,width=740,height=550,top=1');
}