i want to show pagebreak (next prev) only for visitors who came from facebook

i want to show pagebreak post pagination (next prev) only for visitors who came from facebook help me guys

 <?php
            $ref = $_SERVER['HTTP_REFERER'];
            if (strpos($ref, 'facebook.com') != false) {?>

    <!--nextpage-->

  <?php }else{
  echo "";  }
  ?>