How to use the dsm( ) Devel function to print the $form array of my form?
Start a custom module, insert this code:

/**
* Implements hook_form_alter().
*/
function foo_form_alter(&amp;$form, $form_state, $form_id) {
  if ($form_id == 'search_theme_form') {
    dpm($form);
  }
}


Also, you might want to use dpm() over dsm() since the latter is a legacy function.