I am working with with paypal sandbox.
According with that article after IPN verification i need to check payment_gross field but in my case it is empty.
Also i have fields mc_gross and mc_gross_1 which is contains paid amount so should i check mc_gross insteard? any thoughts why payment_gross is empty?
Not sure why payment_gross is empty (or whether or not it should be) but I've always used mc_gross to check the payment amount and I've never had any problems. In fact if memory serves I originally copied that from a PHP code sample from the Paypal developer documents.