function ssaa_theme1(&$existing, $type, $theme, $path) {
    return array(
        'volunteer_node_form' => array(
            'arguments' => array('form' => null),
        ),
    );
}


function ssaa_volunteer_node_form($form) {
    $out = '';
    if (user_is_anonymous()) {
        unset($form['field_active']);
    }
    $out .= drupal_render($form);
    return $out;
}