var prloadedimgs = new Array();
var numimgs = 23;
var i, pcnt = Math.round((Math.random() * (numimgs - 1)) + 1);
for (i = 0; i < 4; i++)
{
 if (pcnt > numimgs)
  pcnt = 1;
 prloadedimgs[i] = new Image();
 prloadedimgs[i].src = "images/bubbles" + pcnt++ + ".jpg";
}
i = 0;
setTimeout("dochange()", 3333);

function dochange()
{
var isIE6 = document.all && document.getElementById;

  if (++i >= 4)
   i = 0;
  if (isIE6)
   document.bubbles.filters[0].apply();
  document.bubbles.src = prloadedimgs[i].src;
  if (isIE6)
   document.bubbles.filters[0].play();
  setTimeout("dochange()", 7890);
}