Support Forum

I'm hoping someone can help me with this as I am sure it is easy and I
just don't know what I am doing.I am trying to add adesense to any forum post. I read
the instructions on the site but am having problems still. When I
save the php file and upload it to the hooks folder within the plug-ins
folder it doesn't work. Instead of placing the ad in the post it places
it in the header for every page of the site. Below is what displays in
the header.

{function sf_hook_first_post($forumid, $topicid) $x = ' '; return $x; }

Warning: session_start()[function.session-start]: Cannot send session
cache limiter – headers already sent (output started at
/home/content/61/6669961/html/wp-content/plugins/simple-forum/forum/hooks/sf-hook-template.php:5)
in
/home/content/61/6669961/html/wp-content/plugins/wp-responder-email-autoresponder-and-newsletter-plugin/wpresponder.php
on line 269

And this is the code in the file I am uploading.

{function sf_hook_first_post($forumid, $topicid)

$x = '<script type="text/javascript"><!–

google_ad_client = "pub-XXXXXXXXXXXX";

/* 234x60, created 9/8/10 */

google_ad_slot = "1443406738";

google_ad_width = 234;

google_ad_height = 60;

//–>

</script>

<script type="text/javascript"

src="http://pagead2.googlesyndication.com/pagead/show_ads.js">

</script>';

return $x;

}

Does any of that even make sense to anyone?