Mon code pour modifier une base de donnée, affiche une erreur à la ligne
WHERE id='$id' ";
voici le code
<?php
$dossier =$_POST['nom_dossier'];
$type_societe =$_POST['type_societe'];
$collaborateur =$_POST['collaborateur'];
$date_cloture =$_POST['date_cloture'];
$type_mission =$_POST['type_mission'];
$tache =$_POST['tache'];
$periodicite =$_POST['periodicite'];
$date_echeance =$_POST['date_echeance'];
$quantite =$_POST['quantite'];
$avancement =$_POST['avancement'];
$commentaire =$_POST['commentaire'];
// on écrit la requête sql
$sql = "UPDATE excel SET nom_dossier='$dossier',
type_societe='$type_societe',
collaborateur='$collaborateur',
date_cloture='$date_cloture',
type_mission='$type_mission',
tache='$tache',
periodicite='$periodicite',
date_echeance='$date_echeance',
quantite='$quantite',
avancement='$avancement',
commentaire='$commentaire'
WHERE id='.$id' ";
// on insère les informations du formulaire dans la table
mysql_query($sql) or die('Erreur SQL !'.$sql.'<br>'.mysql_error());
mysql_close(); // on ferme la connexion
// on affiche le résultat
echo '<strong><center><h1>Le dossier a été modifié.</h1></center></strong>';
?>
C'est quoi mon erreur?le code afficher
<?php
//On verifie que le nom_dossier est defini
if(isset($_GET['id']))
{
$id = intval($_GET['id']);
//On verifie que le nom_dossier existe
$dn = mysql_query('select nom_dossier, type_societe, collaborateur, date_cloture, type_mission,
tache, periodicite, date_echeance, quantite, avancement, commentaire from excel where id="'.$id.'"');
//On affiche les donnees de lutilisateur
$dnn = mysql_fetch_array($dn);
?>
<center><h2> MODIFIER LE DOSSIER
<?php echo htmlentities($dnn['nom_dossier'], ENT_QUOTES, 'UTF-8'); ?>
</h2>
<form method="post" action="modifier_client.php" enctype="multipart/form-data">
<table>
<tr>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>Nom Dossier</td>
<td>
<input name="nom_dossier" type="text" value="<?php echo htmlentities($dnn['nom_dossier'], ENT_QUOTES, 'UTF-8'); ?>" />
</td>
<td> </td>
<td>Type de Société</td>
<td>
<input name="type_societe" type="text" value="<?php echo htmlentities($dnn['type_societe'], ENT_QUOTES, 'UTF-8'); ?>" />
</td>
<td> </td>
<td>Collaborateur *</td>
<td>
<input name="collaborateur" type="text" value="<?php echo htmlentities($dnn['collaborateur'], ENT_QUOTES, 'UTF-8'); ?>"/>
</td>
<td> </td>
<td>Date de cloture</td>
<td>
<input name="date_cloture" type="text" value="<?php echo htmlentities($dnn['date_cloture'], ENT_QUOTES, 'UTF-8'); ?>" />
</td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<tr>
<td>Type de mission</td>
<td>
<input name="type_mission" type="text" value="<?php echo htmlentities($dnn['type_mission'], ENT_QUOTES, 'UTF-8'); ?>" />
</td>
<td> </td>
<td>Tâche</td>
<td>
<input name="tache" type="text" value="<?php echo htmlentities($dnn['tache'], ENT_QUOTES, 'UTF-8'); ?>" />
</td>
<td> </td>
<td>Périodicité</td>
<td>
<input name="periodicite" type="text" value="<?php echo htmlentities($dnn['periodicite'], ENT_QUOTES, 'UTF-8'); ?>" />
</td>
<td> </td>
<td>Date d'échéance</td>
<td>
<input name="date_echeance" type="text" value="<?php echo htmlentities($dnn['date_echeance'], ENT_QUOTES, 'UTF-8'); ?>" />
</td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>Quantité</td>
<td>
<input name="quantite" type="text" value="<?php echo htmlentities($dnn['quantite'], ENT_QUOTES, 'UTF-8'); ?>" />
</td>
<td> </td>
<td>Avancement</td>
<td>
<input name="avancement" type="text" value="<?php echo htmlentities($dnn['avancement'], ENT_QUOTES, 'UTF-8'); ?>" />
</td>
<td> </td>
<td>Commentaire</td>
<td><textarea name="commentaire" rows="3" cols="21">
<?php echo htmlspecialchars($dnn['commentaire'], ENT_QUOTES, 'UTF-8'); ?>
</textarea>
</td>
<td> </td>
<td> </td>
<td> </td>
</tr>
</table>
<center><input type="submit" name="modifier" value="MODIFIER"/></center>
</form>
</center>
<?php
}
else
{
echo 'Ce nom de dossier n\'existe pas.';
}
?>
Merci