Dear perlmonks---I am trying to understand the Business::PayPal module, version 0.04 on cpan. the docs show nicely how to put up a button that gets my user from my website to paypal and which tells my website what '$id' the transaction is going to be. each button I put up gets its own $id. so, if I have 10 users for my scripts, I should have 10 different $id's.

alas, I do not understand the documentation about the return from paypal. there are really simple things that I want to learn:

1. I want one return.cgi script receive many different purchase confirmations. so, I do not want my return.cgi script to provide my stored $id—instead I want the $id to come back from paypal and then have my return.cgi script act on which purchase was just confirmed. (the sample documentation script has me input my $id, but because my return script should work with many purchases, this can't be right.) This is really my main question.
2. I want to write a CLI program that checks automatically whether an $id has been paid. again, this won't be a web program, but a CLI program. the sample program seems to want a whole lot of CGI return information. does someone have a script that shows how to do this?
3. (related) what is an ipnvalidate()? when I use it, the sample doc requires me to have both the $id and all the return info from paypal. Maybe I need this for the answer to my preceding question, which means the $id alone won't be enough (bummer). But, worse, when I tried this, I get a mismatch on the paypal signature.
4. can I give the $paypal->button() method (and thus paypal) my own string in some field, that would also then come back in paypal's query string to return.cgi? this would make it quicker for me to look up what was just paid for.
5. can I tell $paypal->button() to draw a bigger icon?

I am obviously confused. Advice, as always, appreciated.

/iaw