danik.js,
 

 а так? или это не про то?
<!DOCTYPE HTML>
<html>
<head>
  <title>Untitled</title>
</head>
<body>
<script>
document.addEventListener('DOMContentLoaded', function(){
    var script = document.createElement('script');
    script.src = 'data:application/javascript,function%09fn(){alert("ok")}';
    document.head.appendChild(script);
    window.setTimeout('fn()', 0)
    //fn();
});
</script>
</body>
</html>