Google ad sense

okay i tried to add the google adsense meta tag to my site and google can not verify my site. I read that you cant upload an html file to these web sites. Does anyone know where to put this meta tag so google can find my site and verify it? Please help

<script type="text/javascript"><!--
google_ad_client = "pub-5844231171744778";
/* 336x280, created 7/31/08 */
google_ad_slot = "1238146135";
google_ad_width = 336;
google_ad_height = 280;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>