function showGravatarImage($commentID, $class = 'guest')
{
    global $app;
    // SETTING BEGIN
    // Image size
    $size = 32;
    // Gravatar rating
    $rating = 'g';
    // Images altanative text
    $alt = 'His or Her gravatar';
    // SETTING END
    // No object when call from 'recent-comments-text'.
    if (!is_object($app)) {
        $app = new Loggix_Application();
    }
    // Get E-Mail
    $sql = 'SELECT ' . ' user_mail ' . 'FROM ' . COMMENT_TABLE . ' ' . 'WHERE ' . "id = '" . $commentID . "'";
    $res = $app->db->query($sql);
    $userMail = $res->fetchColumn();
    // Default image
    $defaultUrl = preg_match('/admin/', $class) ? $app->getRootUri() . 'theme/css/default/images/icon-admin.png' : $app->getRootUri() . 'theme/css/default/images/icon-guest.png';
    // Make Gravatar URL
    if ($userMail) {
        $imageUrl = 'http://www.gravatar.com/avatar/' . md5(strtolower($userMail)) . '?default=' . urlencode($defaultUrl) . '&size=' . $size . '&rating=' . $rating;
    } else {
        $imageUrl = $defaultUrl;
    }
    return '<img src="' . $imageUrl . '" width="' . $size . '" height="' . $size . '" alt="' . $alt . '" />';
}