Paypal pro IPN sample file

<?
	$req = 'cmd=_notify-validate';
	foreach ($_POST as $key => $value) {
	$value = urlencode(stripslashes($value));
	$req .= "&$key=$value <br />";
	}
 
	$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 ('ssl://www.paypal.com', 443, $errno, $errstr, 30);
	$fp = @fsockopen('ssl://www.sandbox.paypal.com', 443, $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'];
	$custom = $_POST['custom'];
	$receiver_email = $_POST['receiver_email'];
	$payer_email = $_POST['payer_email'];
 
	$notify_email =  $payer_email;         //email address to which debug emails are sent to
 
if ($fp)
{
 
	fputs ($fp, $header . $req);
	while (!feof($fp)) 
	{	
		$res = fgets ($fp, 1024);	
		if (strcmp ($res, "VERIFIED") == 0) {	
 
		// write code when payment is successful
 
		} else if (strcmp ($res,"INVALID") == 0) {
		// code when payment is not successful
		}	
	}
 
	fclose ($fp);
}
else
{
// connection error
}
?>