How to implement different adsense unit for depending on authors..

I pasted the Code You gave me, and changed the author #1 with the authors name and added the adsense code when its says author1 adsense code and author 2 adsense code, this is what i got

<?php
function author_adsence () {
global $post;
global $wpdb;
global $post_id;

$content_new = $content;

if(isset($_GET['author_name'])) :
$author = get_userdata($_GET['author']);
if($author== "madhi"):
$topadsence = <script type="text/javascript"><!--
google_ad_client = "pub-xxxxxxxxxxxxx";
/* 336x280, Large Rec, */
google_ad_slot = "yyyyyyyyyyyy";
google_ad_width = 336;
google_ad_height = 280;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
else:
$bottomadsence = <script type="text/javascript"><!--
google_ad_client = "pub-xxxxxxxxxxxxxxxxxxx";
/* 336x280, Large Rec, */
google_ad_slot = "zzzzzzzzzzz";
google_ad_width = 336;
google_ad_height = 280;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
endif;
else :
$topadsence = <script type="text/javascript"><!--
google_ad_client = "pub-xxxxxxxxxxxxxxx";
/* 336x280, Large Rec, */
google_ad_slot = "yyyyyyyyyyyyyy";
google_ad_width = 336;
google_ad_height = 280;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
endif;
$content_new_with_adsence .=$topadsence;
$content_new_with_adsence .=$content_new;
$content_new_with_adsence .=$bottomadsence;

return $content_new_with_adsence;
}

add_action('the_content', 'author_adsence', 9);
?>