Make Author Field in Comments Required How I could make from my template.php author/user field in comments required for those who are anonymous users

I tried with this but it didn't work for me


  function MYTHEME_theme() { $form['author']['_author']['#required'] =
  TRUE; }


I've been searching around but can't find a proper answer :/
You have to create a little module and implement hook_form_FORM_ID_alter() to alter the form.