function popup(url, x, y, scroll) {
  mywin=window.open(url,'win','width='+x+',height='+y+',scrollbars='+scroll);
  mywin.focus();
}

function confirmation(text) {
  return confirm(text);
}

function pause(numberMillis) {
  var now = new Date();
  var exitTime = now.getTime() + numberMillis;
  while (true) {
    now = new Date();
    if (now.getTime() > exitTime)
    return;
  }
}

function flipImage(nazwa,url) { 
  document[nazwa].src = url; 
}