var popup = null;
function show(nazwa, width, height) {
if (popup) { popup.close(); }
if (!popup || popup.closed) {
popup = window.open("","popup","dependent=no,width="+width+",height="+height+",toolbar=no,menubar=no,status=no,resizable=no");
}
popup.moveTo(0,0); 
popup.location.href = nazwa;
popup.focus();
}