function newImage(arg)
{
  if (document.images)
  {
    rslt = new Image();
    rslt.src = arg;
    return rslt;
  }
}

function changeImages()
{
  if (document.images && (preloadFlag == true))
  {
    for (var i=0; i<changeImages.arguments.length; i+=2)
    {
      document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
    }
  }
}

var preloadFlag = false;
function preloadImages()
{
  if (document.images)
  {
    company_over = newImage("img/company_a.jpg");
    models_over = newImage("img/models_a.jpg");
    history_over = newImage("img/history_a.jpg");
    productions_over = newImage("img/productions_a.jpg");
    feedback_over = newImage("img/feedback_a.jpg");
    preloadFlag = true;
  }
}