session失效，很奇怪的失效解決方案

session失效，很奇怪的失效
這兩天一直在寫paypal, 現在就快把ipn.php整完了，但遇到一個問題讓我很費解啊！
session在ipn.php裡面只有一部分有效，看代碼

PHP code

connect();$listener = new IpnListener();$listener->use_sandbox = true;$order_time=$_SESSION['order_time_org'];$username=$_SESSION['user'];echo "$order_time, $username";//到這裡位置以上，SESSION是可以用的 上面輸出兩個都能顯示出來//下面就顯示不出來了！這是為什嗎？try {    $verified = $listener->processIpn();} catch (Exception $e) {    // fatal error trying to process IPN.    exit(0);}if ($verified) {    // IPN response was "VERIFIED"    //send email form    $invoice_id=$_POST['invoice'];    $payment_status = $_POST['payment_status'];    $receiver_email = $_POST['receiver_email'];    $payer_email = $_POST['payer_email'];    //$order_time = $_POST['custom'];    //$whimwin_user=$_SESSION['user'];        //這裡的$_SESSION['user']顯示不出來啊！    //if($payment_status=="Completed")    //{            $query="UPDATE CART SET payment_status='paid' WHERE username='$username' AND order_time='$order_time' AND invoice_id='$invoice_id'";        $result=queryMysql($query);        if($result)        {            $to="[email protected]";//payer_email            //subject            $subject="Whim Win paid successful!";            //from            $header="from: test <[email protected]>";            //message body            $message="Dear Member, \n\n";            $message.="this is you invoice id $invoice_id \n";            $message.="$payment_status, $order_time, $payer_email, $receiver_email, $username";            //send email            $sendmail=mail($to,$subject,$message,$header);        }    //}} else {    // IPN response was "INVALID"}$db->close();?>

------解決方案--------------------
先測試一下
try {
print_r($_SESSION);
$verified = $listener->processIpn();
print_r($_SESSION);
} catch (Exception $e) {
// fatal error trying to process IPN.
exit(0);
}

------解決方案--------------------
不要去管他，自己緩衝一下
先調通了再說
try {
$mysession = $_SESSION;
$verified = $listener->processIpn();
$_SESSION = $my_session;
} catch (Exception $e) {
// fatal error trying to process IPN.
exit(0);
}
------解決方案--------------------
你這個ipn.php檔案是支付成功的verify頁面吧？我有看到你update支付狀態的sql語句。
如果我猜的沒錯，那麼你要搞清楚的一點是，客戶支付的過程是走瀏覽器,所以cookie頭可以續傳，但是paypal請求你這個頁面通告你支付結果這個流程，是通過palpay服務端完成的,比如我們php常用的curl。所以如果你不是顯式的傳給paypal當前的cookies，然後paypal請求的header頭裡帶上這個cookies，怎麼可能讀到session呢。

