// total number of banner
var totalBanner = 28;
var bannerImageName = 'photo_';
var pics;

function loadBanner()
{
   if ( document.images.banner_rotate )
   {
      pics = new Array( totalBanner );
      for ( var i = 1; i < totalBanner+1; i++ )
      {
         pics[i] = new Image();
         pics[i].src = "http://pro.pictage.com/homepage/" + bannerImageName + i + ".jpg";
      }
      set_image();
   }
}

function set_image( )
{
   choose = Math.ceil( Math.random() * ( totalBanner ) );
   document.images.banner_rotate.src = pics[choose].src;
}