I'm writing a custom module and I'm trying to intergrate Paypal or include a listener for the Paypal IPN system. I got a bit lost trying to work out how this was done before in other plugins, for example the donations plugin. So I went looking at the original source code from the Paypal developers site, I have followed all the instructions but it wouldn't work. After some testing I have realised that the line:

defined('COT_CODE') or die('Wrong URL.');

Blocks any IPNs being recieved by the listener, however if you remove this line it stops any of Cotonti's functions working. Is there a way around this or am I simply doing something wrong? Here is the code for my listener: http://pastebin.com/KxH1BMF0

Thanks, 

Luke.

Added 6 hours later:

Nevermind, problem solved. You can delete this topic.