urgent besoin d'aide pour si quelqu'un connait la répense

<?
require("class.php");
session_start();

?>
<table width="924" border="0">
<!--DWLayoutTable-->
<tr>
<td width="58" height="33"></td>
<td width="2"></td>
<td colspan="3" align="center" valign="top">
<?php
include("haut.php");

?>
&nbsp;</td>
<td width="24">&nbsp;</td>
</tr>
<tr>
<td height="6"></td>
<td></td>
<td width="87"></td>
<td width="682" rowspan="3" valign="top"> <p>&nbsp;</p>
<table align="center" width="273" border="0" cellspacing="0" cellpadding="0">
<!--DWLayoutTable-->
<tbody>
<tr>
<td> <table width="270" border="0" cellspacing="0" cellpadding="0">
<tbody>
<tr>
<td> <table align="CENTER" border="0" cellspacing="0" cellpadding="0">
<tbody>
<tr>
<td align="center"> <table width="272" border="0" cellspacing="0" cellpadding="0" height="15">
<tbody>
<tr>
<td width="13" height="15"><img src="images/bleu_g.gif" alt="" width="13" height="19" border="0"></td>
<td class="menu-bl" bgcolor="#0066CC" height="15" align="CENTER"><strong>Caddie
</strong></td>
<td width="12" height="15"><img src="images/bleu_d.gif" alt="" width="12" height="19" border="0"></td>
</tr>
</tbody>
</table></td>
</tr>
</tbody>
</table></td>
</tr>
</tbody>
</table></td>
<td width="137"></td>
</tr>
</tbody>
</table>
<br> <br> <br> <br> <table width="652" border="1" bgcolor="#0066CC" bordercolor="#FFFFFF" align="center">
<!--DWLayoutTable-->
<tr>
<td width="253" height="23" valign="middle" class="menu-bl" bgcolor="#0066CC" ><strong>&nbsp;&nbsp;Produit</strong></td>
<td width="102" valign="middle" class="menu-bl" bgcolor="#0066CC"><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prix</strong></td>
<td width="66" valign="middle" class="menu-bl" bgcolor="#0066CC"><strong>&nbsp;&nbsp;&nbsp;Qt&eacute;</strong></td>
<td width="102" valign="middle" class="menu-bl" bgcolor="#0066CC"><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total</strong></td>
<td width="95" valign="middle" class="menu-bl" bgcolor="#0066CC"><strong>&nbsp;&nbsp;Supprimer</strong></td>
</tr>
</table>
<?
//passage des variables par adresse
$statut=$_GET['s'];
$titre=$_GET['t'];
$prix=$_GET['p'];
$total=0;


if($titre<>'' and $statut=="a")

{

$_SESSION['pan']->add_item ($titre,1,$prix);
}
if($titre<>'' and $statut=="r")
{
$_SESSION['pan']->remove_item ($titre,1,$prix);
}

if($titre<>'' and $statut=="d")
{
for($i=0;$i<sizeof($_SESSION['pan']->items);$i++)
{
if($_SESSION['pan']->items[$i][0]==$titre)
$_SESSION['pan']->remove_item ($titre,$_SESSION['pan']->items[$i][1],$prix);
}

}


//Affichage du panier

for($i=0;$i<sizeof($_SESSION['pan']->items);$i++)
{
if($_SESSION['pan']->items[$i][1]=='') continue;
}
?>
<table width="652" border="1" bgcolor="#33CCFF" bordercolor="#FFFFFF" align="center">
<!--DWLayoutTable-->
<tr>
<td width="253" height="32" valign="middle" style=" "><font class="menu-no">&nbsp;&nbsp;<? echo ($_SESSION['pan']->items[$i][0])?></font></td>
<td width="102" valign="middle"><font class="menu-no"><? echo str_repeat("&nbsp;",5).($_SESSION['pan']->items[$i][2])?></font></td>
<td width="66" align="center" valign="middle"><font class="menu-no">
<a href="cad.php?t=<? echo $_SESSION['pan']->items[$i][0]?>&p=<? echo $_SESSION['pan']->items[$i][2]?>&s=r">-</a>
<input name="" type="text" size="2" value="<? echo ($_SESSION['pan']->items[$i][1])?>" readonly="yes">
<a href="cad.php?t=<? echo $_SESSION['pan']->items[$i][0]?>&p=<? echo $_SESSION['pan']->items[$i][2]?>&s=a">+</a>
</font></td>
<td width="102" valign="middle"><font class="menu-no"><? echo str_repeat("&nbsp;",5).number_format(($_SESSION['pan']->items[$i][1]*$_SESSION['pan']->items[$i][2]),3)?></font></td>
<td width="95" valign="middle"><font class="menu-no"><a href="cad.php?t=<? echo $_SESSION['pan']->items[$i][0]?>&p=<? echo $_SESSION['pan']->items[$i][2]?>&s=d">&nbsp;&nbsp;&nbsp;&nbsp;Supprimer</a></font></td>
</tr>
</table>
<?
$total=$total+ $_SESSION['pan']->items[$i][1]*$_SESSION['pan']->items[$i][2];

echo "<br>"."<br>"."<font class=\"menu-no\">"."&nbsp;&nbsp;Le montant Total de votre commande : ".number_format("$total",3)." dinars"."</font>";
echo "<br><br><br>"."<center>"."<a href=\"comm.php?v=1\">Commander</a>"."</center>";
?>

</td>
<td></td>
</tr>
<tr>
<td height="374" valign="top">
<? include ("menu.php");?>
</td>
<td></td>
<td></td>
<td></td>
<td>&nbsp;</td>
</tr>
<tr>
<td height="16"></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td height="1"></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
</table>
pourkoi le serveur me signale erreur pour la ligne $_session['pan']-> add item($titre, 1, $prix)sachant que je travaille avec php 5

atheka ech 9ader 3lik rabi inwebo