popup="";
function okno(arg,s,x,y) {
  if (popup == '[object]') {popup.close()} else {}
  scr_width = screen.availWidth;
  scr_height = screen.availHeight;
  left_align = eval(scr_width/2)-eval(x/2);
  top_align = eval(scr_height/2)-eval(y/2);
  popup=window.open(arg,'szczegoly','toolbar=0,location=0,direction=0,status=0,resize=1,menubar=0,scrollbars='+s+',width='+x+',height='+y+',left='+left_align+',top='+top_align);
}
function valid_mail(co) { return (/^[\w\.-]{2,}@[\w\.-]+\.[a-z]{2,5}$/i.test(co)); }
function externalLinks() {
  if (!document.getElementsByTagName) return;
  var anchors = document.getElementsByTagName("a");
  for (var i=0; i<anchors.length; i++) {
    var anchor = anchors[i];
    if (anchor.getAttribute("href")&&anchor.getAttribute("rel")=="external") anchor.target="_blank";
  }
}