function e_edo_add_content($content)
{
    if (is_page() || is_single()) {
        global $more;
        $more = 0;
        $content = get_the_content('');
        $content .= get_addtional_content();
        $more = 1;
        $content .= get_the_content('', true);
    }
    return $content;
}
function e_edo_add_content($content)
{
    if (is_admin()) {
        return $content;
    }
    if (is_page() || is_single()) {
        $before = get_addtional_content();
        $after = get_addtional_content('after');
        if (!empty($before)) {
            $content = preg_replace('/(<span id="more-[0-9]+">.*?<\\/span>)/', $before . '$1', $content);
        }
        if (!empty($after)) {
            $content = preg_replace('/(<span id="more-[0-9]+">.*?<\\/span>)/', '$1' . $after, $content);
        }
    }
    return $content;
}