paypal ipn, please help

[candle21428]

For some reasons the following code is not working (the "echo" results in nothing, a blank page)

Here is the code:

session_start();
include 'config.php';
$req = 'cmd=_notify-validate';
foreach ($_POST as $key => $value) {
$value = urlencode(stripslashes($value));
$req .= "&$key=$value";
}
$header .= "POST /cgi-bin/webscr HTTP/1.0\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($req) . "\r\n\r\n";
$fp = fsockopen ('www.sandbox.paypal.com', 80, $errno, $errstr, 30);
$item_name = $_POST['item_name'];
$item_number = $_POST['item_number'];
$payment_status = $_POST['payment_status'];
$payment_amount = $_POST['mc_gross'];
$payment_currency = $_POST['mc_currency'];
$txn_id = $_POST['txn_id'];
$receiver_email = $_POST['receiver_email'];
$payer_email = $_POST['payer_email'];
$payment_date = date("Y-m-d");
$_SESSION['test']=$item_name;
echo $_SESSION['test'];

I run thru the whole process: make payment using my sandbox account ==> the transaction shown up properly in the sandbox account. However, the paypal.php page showed nothing (It should at least show something one the page [item name?] if there is any data from paypal sandbox)

What should I do to fix the code?

[sneakyimp]

well first off, is that it's paypal's server connecting to that page, not you.

secondly, paypal's server doesn't do anything at all with what you echo from your ipn page as far as i know. by the time paypal is posting your ipn page, i think the transaction is all done with - you can't stop it from your ipn page.

if you want to know what information is going to your ipn page, you'll need your ipn page to write it to a log file or stick it in a database...or email you. emailing is probably the simplest. replace that echo line with something like this:

mail('[e-mail]', 'SOMEONE CONTACTED YOUR PAYPAL IPN PAGE', print_r($_POST, true));