(function($) {
  var cache = [];
  // Arguments are image paths relative to the current page.
  $.preLoadImages = function() {
    var args_len = arguments.length;
    for (var i = args_len; i--;) {
      var cacheImage = document.createElement('img');
      cacheImage.src = arguments[i];
      cache.push(cacheImage);
    }
  }
})(jQuery)

jQuery.preLoadImages("images/firma_over.gif", "images/home_over.gif", "images/kontakt_over.gif", "images/news_over.gif", "images/oferta_over.gif", "images/online_over.gif", "images/promo_over.gif", "images/wspolpraca_over.gif", "images/wycen_over.gif");