How to achieve full screen mode on page load using jquery or javascript

Unfortunately this works only on Button click and not on page load

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/javascript" src="http://www.ailis.de/~k/scripts/jquery/plugins/fullscreen.js"></script>
    <script type="text/javascript">
        $("#btn").live("click", function () {
            $(document).fullScreen(true);
        });
    </script>
    <input type="button" id="btn" value="btn" />

Meaning it has to be triggered by some user