Process the language editing form submission.
function language_admin_edit_form_submit($form, &$form_state) {
// Prepare a language object for saving.
$languages = language_list();
$langcode = $form_state['values']['langcode'];
$language = $languages[$langcode];
$language->name = $form_state['values']['name'];
$language->direction = $form_state['values']['direction'];
language_save($language);
$form_state['redirect'] = 'admin/config/regional/language';
}