Untitled

jquery, save entire DOM for reloading
<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<title></title>

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script type="text/javascript">

    $(function(){

        var xml = '<?xml version="1.0"?><foo><bar>bar</bar></foo>';

        document.open("text/xml", "replace");
        document.write(xml);

        document.execCommand('SaveAs',true,'file.xml');

    });

</script>

 </head>
<body>

</body>
</html>

popup.document.open("text/xml", "replace");
    popup.document.write(xml);

    popup.document.execCommand('SaveAs',true,'file.xml');
    popup.close();
});