title: Drupal 7 : Advanced theme settings after submission
body: <p>I have a problem with advanced settings in theme-settings.php. i can build custom form with this --></p>
  
  <pre><code>mytheme_form_system_theme_settings_alter(&amp;$form, &amp;$form_state) {
   //custom form
  }
  </code></pre>
  
  <p>function. But how i can integrate new function after settings submission? like this:</p>
  
  <pre><code>mytheme_system_theme_settings_submit_alter($form, &amp;$form_state) {
    // if form submited -&gt; execute function
  }
  </code></pre>