A CodeIgniter dynamic dropdown to allow common languages to appear both at the top of the list and in order

CI dynamic dropdown

function full_languages_dropdown($id='' )
{
    $ci = &get_instance();

    $ci->load->model('language_model');
    $common_languages = $ci->language_model->order_by('language', 'asc')->get_many_by(array('common'=>1));     
    $languages = $ci->language_model->order_by('language', 'asc')->dropdown('id', 'language');   

    $html = '<select id="'.$id.'" name="'.$id.'">';

    if (!empty($common_languages))
    {
        foreach ($common_languages as $key => $common_language) {
            $html .= '<option value="'. $common_language->id .'">'. $common_language->language .'</option>';
        }
        //separator
        $html .= '<option value=""> ------ </option>';
    }

    if (!empty($languages))
    {
        foreach ($languages as $key => $language) {
            $html .= '<option value="'. $key .'">'. $language .'</option>';
        }
    }

    $html .= '</select>';

    return $html;            

}