I do put it in a database but generally those DB's are never the same.  I use this with lots of different clients.  It's just a starting point for me so I can begin immediatly with all possible data available to me in PHP variables.

Usually what I do is then add include files to handle each particular task the listener might handle.  For example, I use this with one client of mine to handle their eBay checkouts and get those orders into their database.  I have an include that runs if the IPN came from an eBay checkout.  I can easily add the IPN data to their system using this template.  I just had to add in the actual database inserts.  Another client might have completely different tables and fields names.

Another include could be used to handle disputes, and another to handle echecks, etc.  Some of my clients use mysql, some use Access, some use FileMaker...can't really handle the DB end of things for everybody.

Is it better to use ssl or not?

Also, which of these variables do I need to check out in order to know that I receieved money?

Basically, I need to know that no matter what method that they used, that I actually got paid and that its actually in my account so that my php script can alter their info on my site. I also have one custom variable that needs to give me their account id from my site, which I have in my form.

If SSL is available I recommend using it. 

To ensure a payment has been completed you can use a combination of the following fields: $txn_type, $payment_type, $payment_status, $pending_reason.  Study those fields here and you should be able to figure it out.

Angeleye,

Why can't you simply check if $payment_status equals  "Completed" to ensure payment has been completed? You don't need to know txn_type,  payment_type, and pending_reason... do you?

grimholtz