function zmien_fotos(x, ile, now) {
  for (var i=1; i<=ile; i++) {
   $('#kalendarz'+i).css({opacity:0.0});
  }
  $('#kalendarz'+x).css({opacity:1});

  var n;
  //alert(now);
  if (x=='left') {
   n = now;
   now--;
   if (now==0) now=ile;

   $('#kalendarz'+n).animate({opacity:0.0},1000);
   document.getElementById('kalendarz'+n).style.display="none";
   document.getElementById('kalendarz'+now).style.display="inline";
   $('#kalendarz'+now).animate({opacity:1},1000);

  } else {
   n = now;
   now++;
   if (now>ile) now=1;

   $('#kalendarz'+n).animate({opacity:0.0},1000);
   document.getElementById('kalendarz'+n).style.display="none";
   document.getElementById('kalendarz'+now).style.display="inline";
   $('#kalendarz'+now).animate({opacity:1},1000);

  }
}