I have paypal with ipn working perfect since a week,
however yesterday there were for some reason 12 hours delay for the ipn, so with the cronjob the items purchased were canceles, as did not get ok from paypal.
So now I am trying to add pdt, data transfer also, to use both of them.
I dont get it
I have tried several examples and tutorials, and I dont get any to work. No error message or ok, nothing.

This is the last I am trying:

And it starts with just simple php to check if we get the tx from the url.
(the url I receive looks like this:
mysite.com/bookingcheckout.php?tx=8EN70956P3515601S&st=Completed&amt=2.00&cc=EUR&cm=3768&item_number= )

I start with this as says in tutorial, and not even this works...
$tx = $_GET['tx'];
// Further processing
echo "ok";

Just dont know which to try anymore, the one in paypal is php 5.3 and I have 5.2 so I tried the curl one and did not work either....