Esto debería ir en otra parte ya que no es
PHP Cita: Modifying the Query String
By default, the query string is passed through unchanged. You can, however, create URLs in the substitution string containing a query string part. Simply use a question mark inside the substitution string to indicate that the following text should be re-injected into the query string. When you want to erase an existing query string, end the substitution string with just a question mark. To combine new and old query strings, use the [QSA] flag.
De la página de apache, asi que saca el QSA conta el resultado.