Random background details..., help Options

[plainshane]

Well this is the code I have in my Custom Header for the background: random script.

CODE

<!-- begin code provided by createblog.com -->
<!-- begin code provided by createblog.com -->

<script type='text/javascript'>
// random background - jammers

var image = new Array();

// change up the images here
image[0] = 'http://webpages.charter.net/scgumby/xanga3.jpg';
image[1] = 'http://skins3.wincustomize.com/GreenArmani/wallpapers/Sable1024x768.jpg';
image[2] = 'http://www.billabong.com/en/images/img_gallery_wallpapers/NA/800x600_grub_1.jpg';

var index = Math.floor(Math.random() * image.length);
document.write('<style type="text/css"> body { background-image: url('+ image[index] +')</style>');
</script>
<!-- end code provided by createblog.com -->
<!-- end code provided by createblog.com -->

Now... it won't work. Do I need to get rid of my original custom background image I had entered or what? Is the process just putting that code into the custom header or is there more? Thanks