PHP Clean URL for SEO

function seo_uri($phrase, $maxLength=50){
  $result = strtolower($phrase);
  $result = preg_replace("/[^a-z0-9\s-]/", "", $result);
  $result = trim(preg_replace("/[\s-]+/", " ", $result));
  $result = trim(substr($result, 0, $maxLength));
  $result = preg_replace("/\s/", "-", $result);
  return $result;
}