function preload()
{
  for(var i=0;i<document.images.length;i++)
  {
    if(!document.images[i].complete)
    {
      document.images[i].style.background='url(loading_kolo.gif)';
      document.images[i].style.visibility='hidden';
      document.images[i].onload=function()
      {
        this.style.visibility='visible';
        this.style.background='none';
      };
    }
  }
}

//preload();