Adsense: You don't have a mobile website

In order to use Adsense for mobile content, you must have a mobile-compliant webpage; adding Adsense for mobile ad code to a standard webpage will not display ads.
If you don't currently have a mobile website (and chances are, if you're not sure, then you don't have one). You can create one by rewriting your existing in a mobile markup language, such as XHTM, WML, or CHTML. You'll also need to make sure the layout of your website is properly formatted to display on mobile phones.
In addition, your mobile website will need to be developed using server-side scripting such as PHP or ASP. Many web hosting providers support PHP, and in many case, you can PHP-enable your webpages simply by changing the file extension from .htm to .php. The reafter you can paste PHP code snippset into the section of the page where you want the Adsense for mobile ads to appear.
Keep in mind that Google will not be able to assist yot with creating a mobile website. However, you may be able to find resources on the web that could help you create a mobile site. We suggest doing "Google search for term such as" create mobile website or "make mobile web page ".
Once you've create a mobile webpage that comlies with our program policies, you're wellcome to add Google ads to it!
From: adsense suport