Support for multilanguage sites, Internationalization (I18N)

[polyfragmented]

Got it!

Code:

<?php
     // Check whether the return_i18n_menu_data array has no elements for the submenu
    // 'return_page_slug(),1,10' is the same as in 'get_i18n_navigation(return_page_slug(),1,10);'
    // to call up the submenu

    if (count(return_i18n_menu_data(return_page_slug(),1,10)) == 0) {

        echo 'Es gibt in diesem Bereich keine Unterseiten.';

    } else {

        get_i18n_navigation(return_page_slug(),1,10);

    }
?>

Now works, thanks for the hint.