Fusion theme classes for node add and node edit pages

I almost always use Fusion theme as my base theme, one thing its missing and developers of it seem not to care is a class that is in body and is different for node add and node edit pages, so I usually go to template.php and around line 64, after

  else {
    $body_classes[] = (arg(0) == 'forum') ? 'forum' : '';                                            // Forum page
  }

I add this two

   $body_classes[] = (arg(1) == 'add') ? 'node-edit' : '';   
   $body_classes[] = (arg(2) == 'edit') ? 'node-edit' : '';