Hey @Gih, I moved the topic to the CMS & WordPress category, hope that’s OK. :-) Now what exactly is that button supposed to do? It seems you are confusing two different things here… clicking a button is a browser event, so the PHP scripts have already run and served a given page (the admin panel in that case). The add_action() function however hooks a function to an action during the server side script execution. Now what you can do is setting a value in the database when you click the button (although you’ll usually submit a whole form with some given options), and check for that value somewhere in your functions.php.