Parce erreur

$_SESSION['id_prop']=NULL ;
 $bdd = new PDO('mysql:host=localhost;dbname=covoiturage','root','') ;
$requete = $bdd->prepare('SELECT * FROM trajet,reservation WHERE trajet.id_trajet = reservation.id_trajet AND trajet.id_pers = ? AND reservation.reponde="attente"');
 $requete->execute(array($_SESSION['id_pers'])); 
while($data = $requete -> fetch()){
 $_SESSION['id_prop']=$data['id_pers'] ;
  $_SESSION['id_reservateur']=$data['id_reservateur'] ;
  $_SESSION['reponde'] = $data['reponde'] ;
 $_SESSION['id_trajet'] = $data['id_trajet'] ;  
 }
 $requete->closeCursor() ;
 
 
 
 if($_SESSION['id_prop']==$_SESSION['id_pers'] AND $_SESSION['reponde']=="attente")
 {


 

 ?>
 <br><br><br><br><br>
 <center>
 <table style="width:400px;height:250px;background-color:#FF7F50 ">
 <form  method=POST action=logon_drt_bas.php>
 
<tr>
<td>
<br><br>
<?php
  echo '<div class ="div1"><center><h3> <div class ="div4">'.$_SESSION['pseudo_nom'].' </div></h3></center></div>' ;
  ?>
  <br>
<div class ="div1"><center><?php  echo 'Vous avez '. $requete->rowCount() .' demmandes de reservation reponder les' ;}?></center></div> </td>
  
  
  </tr>
 <tr>
  <td>
 
  <div class="buttons" style="margin-bottom:30px"><strong><center><input type="submit" name=reponder value="Reponder"></center></strong></div>
  </td> </tr>
  </form>
   </table></center>
   
<?php
}//................................................l'erreur est ici

else
{
echo'aucune demmande de reservation';
} 

if(isset($_POST['reponder']))
 {
  $bdd = new PDO('mysql:host=localhost;dbname=covoiturage','root','') ;
$requete = $bdd->prepare('SELECT * FROM personne WHERE personne.id_pers = ?');
 $requete->execute(array(  $_SESSION['id_reservateur'])); 
while($data = $requete -> fetch()){
?>
 <table style="width:400px;height:250px;background-color:#FF7F50 ">
 <form  method=POST action=logon_drt_bas.php>
 <tr>
<td>
<br><br>
<?php
echo $data['nom'].' '.$data['prenom'].'demmandes de voyager avec vous <br> Qui est : '.$data['etat_soci'].'<br>' ;
?>
</td>
</tr>
<tr>
<td>
<br>
<strong><center><input type="submit" name=confirmer value="Confirmer"></center></strong>
</td>
<td>
<strong><center><input type="submit" name=refuser value="Refuser"></center></strong>
</td>
</tr>
</form>
</table>
<?php
 } 
 $requete->closeCursor() ;
 
  }//..............reponder...//
 

if(isset($_POST['confirmer']))
 {
  $bdd = new PDO('mysql:host=localhost;dbname=covoiturage','root','') ;
$requete = $bdd->prepare('UPDATE reservation SET reponde="confirme" WHERE reponde="attente" AND id_trajet=?');
$requete->execute(array(  $_SESSION['id_trajet'])); 
while($data = $requete -> fetch()){


 } 
 $requete->closeCursor() ;
  }