Any reason this code should not work in define_main_page?

here it is working: http://lekefly.com/test/test222.html

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Slideshow 2!</title>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<meta name="author" content="Aeron Glemann (http://www.electricprism.com/aeron/)" />
<link rel="stylesheet" type="text/css" href="css/slideshow.css" media="screen" />
<script type="text/javascript" src="js/mootools.js"></script>
<script type="text/javascript" src="js/slideshow.js"></script>


<script type="text/javascript">


//<![CDATA[
var dataA = {
'1.jpg': { caption: 'Volcano Asención in Ometepe, Nicaragua.', href: 'keylin.html' },
'2.jpg': { caption: 'A Ceibu tree.', href: 'keylin.html' }
};

var dataB = {
'3.jpg': { caption: 'The view from Volcano Maderas.', href: 'keylin.html' },
'4.jpg': { caption: 'Beer and ice cream.', href: 'keylin.html' }
};

window.addEvent('domready', function(){
myShow = new Slideshow('show1', dataB, { height: 203, hu: 'images/', thumbnails: false, width: 302});
myShow = new Slideshow('show2', dataA, { height: 203, hu: 'images/', thumbnails: false, width: 302});
});
//]]>
</script>

</head>

<body>
<div id="show1" class="slideshow">
<img src="images/3.jpg" />


</div>

<div id="show2" class="slideshow">
<img src="images/1.jpg" />


</div>