Cacher le champ nom d'utilisateur et l'alimenter automatique via 2 champs de mon formulaire ?

/
* @file
* For registration process without a username
*
*/

/
* Implementation of hook_user().
*
*/
function email_registration_user($op, &$edit, &$account, $category = NULL) {
  switch ($op) {
    case 'insert':
      // Other modules may implement hook_email_registration_name($edit, $account)
      // to generate a username (return a string to be used as the username, NULL
      // to have email_registration generate it)
      $names = module_invoke_all('email_registration_name', $edit, $account);
      // Remove any empty entries
      $names = array_filter($names);

$field_nickname = $_POST["field_nickname"][0]["value"];
    $namenew = ucwords($field_nickname);
   $field_family_name = $_POST["field_family_name"][0]["value"];
  $namenew .= ' ' . strtoupper($field_family_name);

      if (empty($names)) {
        // Default implementation of name generation
        #$namenew = preg_replace('/@.*$/', '', $edit['mail']);
        // Remove unwanted characters
        #$namenew = preg_replace('/[^a-zA-Z0-9.-]/', '', $namenew);

        // if username generated from email record already exists, append underscore and number eg:(chris_123)
        #if (db_result(db_query("SELECT count(*) FROM {users} WHERE uid <> %d AND LOWER(name) = LOWER('%s')", $account->uid, $namenew)) > 0) {
          // find the next number available to append to the name
         # $sql = "SELECT SUBSTRING_INDEX(name,'_',-1) FROM {users} WHERE name REGEXP '%s' ORDER BY CAST(SUBSTRING_INDEX(name,'_',-1) AS UNSIGNED) DESC LIMIT 1";
         # $nameidx = db_result(db_query($sql, '^'. $namenew .'_[0-9]+$'));
         # $namenew .= '_'. ($nameidx + 1);
        #}
      }
      else {
        // One would expect a single implementation of the hook, but if there
        // are multiples out there use the last one
        #$namenew = array_pop($names);
      }

      // replace with generated username
      if (db_query("UPDATE {users} SET name = '%s' WHERE uid = '%s'", $namenew, $account->uid)) {
       $edit['name'] = $namenew; // update in the user array for access by other modules
      }

      // if email verification is off and a new user is the one creating account, log the new user in with correct name
      global $user;
      if (!variable_get('user_email_verification', 1) && $user->uid == 0) {
        $user = $account;
        $user->name = $namenew;
      }
      $account->name = $namenew;
      break;
  }
  return;
}

/
* Implementation of hook_form_alter().
*
*/
function email_registration_form_alter(&$form, $form_state, $form_id) {
  switch ($form_id) {
    case 'user_register':
      if (isset($form['account']) && is_array($form['account'])) {
        $form['account']['name']['#type'] = 'hidden';
        $form['account']['name']['#value'] = user_password();
        $form['account']['mail']['#title'] = t('E-mail');
      }
      else {
        $form['name']['#type'] = 'hidden';
        $form['name']['#value'] = user_password();
        $form['mail']['#title'] = t('E-mail');
      }
      $form['#submit'][] = 'custom_email_registration_name_submit';
      break;

/
* Custom submit handler to fix redirect for immediate logins
* #648450
*
*/
function custom_email_registration_name_submit($form, &$form_state) {
  if (!isset($form_state['user'])) {
    return;
  }

  $admin = user_access('administer users');
  $account = $form_state['user'];

  if (!variable_get('user_email_verification', TRUE) && $account->status && !$admin) {
    // No e-mail verification is required, create new user account, and login
    // user immediately.
    $auth = array(
      'pass' => $form_state['values']['pass'],
      'name' => $account->name,
    );
    if (user_authenticate($auth)) {
      // Authenticated, add a message and go to the users account
      // Since the standard workflow doesn't work, no other messages should appear.
      drupal_set_message(t('Registration successful. You are now logged in.'));
      $form_state['redirect'] = 'user/'. $account->uid;
    }
  }
}