var banArray = new Array(3)

var counter = 1;


 if(document.images)

{
  for(i = 0; i < 4; i++)

  {

    banArray[i] = new Image(495, 240);
    banArray[i].src = "banners/baner" + (i+1) + ".jpg";

  }

}

 function changeBanner() 

{

  if(counter > 2)
     counter = 0;

     document.banner.src = banArray[counter].src;
    
     counter++; 

}

 var timer = window.setInterval("changeBanner()", 6000);