Add mootools in Facebook iframe

I'm a beginner with Facebook Iframe.

This code works well on my page:

<script src="js/mootools-1.2.4-core-yc.js" type="text/javascript" charset="utf-8"></script>
    <script src="js/Bubble.js" type="text/javascript" charset="utf-8"&开发者_StackOverflowgt;</script>
    <script type="text/javascript" charset="utf-8">
        window.addEvent('domready', function(){
            var positions_for_demo = ['above', 'below', 'left', 'right'];
            $$('.bubble_me').each(function(item){
                new Bubble(item,{
                    position: positions_for_demo.getRandom()
                });
            });
        });
    </script>

But, doesn't work in the Facebook iframe...

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You cannot access window element on facebook iframe.