function pager_navigation($pager, $uri)
{
  $navigation = '';
 
  if ($pager->haveToPaginate())
  {  
    $uri .= (preg_match('/\?/', $uri) ? '&' : '?').'page=';
 
    // First and previous page
    if ($pager->getPage() != 1)
    {
      $navigation .= link_to(image_tag('first.gif', 'align=absmiddle'), $uri.'1');
      $navigation .= link_to(image_tag('previous.gif', 'align=absmiddle'), $uri.$pager->getPreviousPage()).' ';
    }
 
    // Pages one by one
    $links = array();
    foreach ($pager->getLinks() as $page)
    {
      $links[] = link_to_unless($page == $pager->getPage(), $page, $uri.$page);
    }
    $navigation .= join('  ', $links);
 
    // Next and last page
    if ($pager->getPage() != $pager->getCurrentMaxLink())
    {
      $navigation .= ' '.link_to(image_tag('next.gif', 'align=absmiddle'), $uri.$pager->getNextPage());
      $navigation .= link_to(image_tag('last.gif', 'align=absmiddle'), $uri.$pager->getLastPage());
    }
 
  }
 
  return $navigation;
}