function kosarica(zahteva, artikel) {
   var url = 'kosarica.php';
   var params = 'zahteva=' + zahteva + '&artikel=' + artikel;
   var ajax = new Ajax.Updater(
	          {success: 'cartResult'},
              url,
              {method: 'get', parameters: params, onFailure: porociloNapaka});
              
  newImage = "url(images/image_041.jpg)";
  document.getElementById('ozadjekos').style.backgroundImage = newImage;

}

function porociloNapaka(request) {
   $F('cartResult') = "Zgodila se je napaka!";
}