I have a question about the PayPal IPN payment module when used on multiple sites.... When setting up the module, you are instructed to enter
http://www.myfirstwebsite.com/ipn_main_handler.php

as your Instant Payment Notification Preferences URL and

http://www.myfirstwebsite.com/index.php?main_page=checkout_process

as the Website Payment Preferences > Automatic Return URL

When setting this up for a second site, you are instructed to
the Instant Payment Notification Preferences URL the
same and enter the new URL of
http://www.mysecondebsite.com/index.php?main_page=checkout_process

as the Website Payment Preferences ? Automatic Return URL...

If the IPN URL is the same for both sites, how will PayPal differentiate
between the sites and process the payment accordingly? Should I
setup a different account for each site? Will this actually work?

I'm sure this has been very well thought out, but I have never
dealt with PayPal and have decided to add it as a payment option
for my customers and really need to know the details on how
this will work.

Any input would be appreciated.

Thanks in advance!

Nelson