/**
 * Implements theme_breadcrumb().
 */
function theme_breadcrumb($variables) {
  // global variable
  $output = '';
  $breadcrumb = $variables['breadcrumb'];
  if (!empty($breadcrumb)) {
    $nid = arg(1);
    $node = node_load($nid);
    $output = '<ul class="breadcrumb">';
      if ($node->type == 'content_type') {
        $output .= '<li><a href="' . url() . '" rel="breadcrumb">' .  $node->type . '</a></li>';
      }
    $output .= '<li class="active">'. drupal_get_title() .'</li>';
    $output .= '</ul>';
  }
}