Randomize flash background

How to make a randomize flash background?
I have a script to randomize image

Code:

---

<style type="text/css">
body {
        background-repeat:no-repeat;
        background-position:center top;
 }
</style>

<script type="text/javascript">

  var num;
  var temp=0;
  var speed=20000; /* this is set for 5 seconds, edit value to suit requirements */
  var preloads=[];

/* add any number of images here */

preload(
        'images/bg_home_1.jpg',
        'images/bg_home_6.jpg',
        'images/bg_home_7.jpg'
      );

function preload(){

for(var c=0;c<arguments.length;c++) {
  preloads[preloads.length]=new Image();
  preloads[preloads.length-1].src=arguments[c];
  }
 }

function rotateImages() {
  num=Math.floor(Math.random()*preloads.length);
if(num==temp){
  rotateImages();
 }
else {
  document.body.style.backgroundImage='url('+preloads[num].src+')';
  temp=num;

setTimeout(function(){rotateImages()},speed);
  }
 }

if(window.addEventListener){
  window.addEventListener('load',rotateImages,false);
 }
else {
if(window.attachEvent){
  window.attachEvent('onload',rotateImages);
  }
 }
</script>

---

But it don't work when i try to change the image / .jpg with flash / .swf
Thx in advanced...

so is there any suggestion, i try a lot of different thing to make this work. But it always fail.

i still use image random, till i found the flash randomize script

this is my website, if you need some clue about the problem:)

http://www.imaxxo.net/aryaduta

Thx in advanced