[Deceptor]

Well after testing, it seems createElement() does work for loading JS files after the page has loaded, which is nice

Try this:

<script type="text/javascript">
<!--

function load_ads(url, appendobj)
{
	ads = document.createElement('script');
	ads.src = url;
	ads.type = 'text/javascript';

	document.getElementById(appendobj).appendChild(ads);
}

load_ads('YOUR_SCRIPT_URL', 'YOUR_APPEND_OBJECT');

-->
</script>

Change:

load_ads('YOUR_SCRIPT_URL', 'YOUR_APPEND_OBJECT');

For the url, use the URL to the js file, as for "YOUR_APPEND_OBJECT", it would be: navbar_720x90