Edit the _main.php thats related to the natural Pink skin

Each skin has it's own _main.php file

/skins/naturalpink/_main.php

Simply copy your Adsense code into the new _main.php file

John wrote:

Edit the _main.php thats related to the natural Pink skin

Each skin has it's own _main.php file

/skins/naturalpink/_main.php

Simply copy your Adsense code into the new _main.php file

when i click to template to edit the skin it say i can only edit the custom skin

Use FTP
find the associated _main.php and edit it, then upload it again.

Another way to do this, if you want to use the template tab in your back office, is to first (via FTP or your host's file manager utility) rename the custom skin as something like "custom_original", then rename "nifty_pink" to "custom". That way the template tag will do what it does: edit the files in the custom skin.

The drawback is that you'll be using an icky dumb editor. Much better to do like John says. Get a "smart" editor and an FTP client, edit your files on your PC, and upload them to your server.

By "smart" editor I mean it shows you syntax with color highlighting. There are many available that do this. My favorite is HTML-Kit because it is free and does the job nicely.