Including javascript in form alter

hook_form_alter

/**
 * Implements hook_form_alter().
 */
function fortytwo_form_alter(&$form, &$form_state, $form_id) {
  switch ($form_id) {
    case 'block_admin_display_form':
      $form['#attached']['js'] = array(
        drupal_get_path('theme', 'fortytwo') . '/js/mousetrap.js' => array(
          'scope' => 'footer',
        ),
        '(function() {Mousetrap.bind("mod+shift+s", function() { document.getElementById("' . $form['#id'] . '").submit(); }); }) ();' => array('type' => 'inline', 'scope' => 'footer'),
      );
      break;
  }
}