function slug($text){


  // replace non letter or digits by -


  $text = preg_replace('~[^pLd]+~u', '-', $text);


  // transliterate


  $text = iconv('utf-8', 'us-ascii//TRANSLIT', $text);


  // remove unwanted characters


  $text = preg_replace('~[^-w]+~', '', $text);


  // trim


  $text = trim($text, '-');


  // remove duplicate -


  $text = preg_replace('~-+~', '-', $text);


  // lowercase


  $text = strtolower($text);


  if (empty($text)) {


    return 'n-a';


  }


  return $text;


}