My b2evolution Version: 2.x

I have a Google text advert appearing after the first post using a very old code by some guru I can't remember.....

	<?php
    if ( empty( $shown_advert) || ! $shown_advert )
    {
?>
<p class="money">
Google Ad code inserted here
</p>

<?php
      $shown_advert = 1;
    }
 } // ---------------------------------- END OF POSTS ------------------------------------ ?>

I also have a second advert hard coded into .index.main.php to appear at the bottom of the page...

// ------------------------- END OF MAIN CONTENT TEMPLATE ---------------------------
	?>
<p class="money">
	Google Ad code.....
</p></div>

The problem is that in Single post view or Post Comment view, I end up with two Ads at the bottom of the page.

Is there something I can wrap the second Ad with that says "this is a single post view so go hide yourself" ?