If you have php enabled on the site you are trying to do this on you can simple replace the .html at the end and put a .php and then the following will work.
Instead of using <script src="thescript.js" ></script> you can add <?php include "ads.inc"; ?>
And then in the same directory just add this file as ads.inc(it doesn't really matter what extension you give the file, as long as it matches.
Code:
<!-- Begin: AdBrite -->
<script type="text/javascript">
var AdBrite_Title_Color = '660000';
var AdBrite_Text_Color = '000000';
var AdBrite_Background_Color = 'FFCC66';
var AdBrite_Border_Color = '660000';
var AdBrite_URL_Color = '008000';
</script>
<span style="white-space:nowrap;"><script src="http://ads.adbrite.com/mb/text_group.php?sid=658305&zs=3732385f3930" type="text/javascript"></script><!--
--><a target="_top" href="http://www.adbrite.com/mb/commerce/purchase_form.php?opid=658305&afsid=1"><img src="http://files.adbrite.com/mb/images/adbrite-your-ad-here-leaderboard-w.gif" style="background-color:#660000;border:none;padding:0;margin:0;" alt="Your Ad Here" width="14" height="90" border="0" /></a></span>
<!-- End: AdBrite -->
Or you could just put that html/javascript in the original website, your choice.
Do you understand?