I am trying to integrate PayPal through authorize.net, and can't find any documentation about how to send something that will end up being stored in "invoice id" when you later look at the transaction on authorize.net. There is a reference ID listed, but that doesn't seem to actually count as the invoice id when I look in authorize.net at a finished transaction. The documentation for PayPal authorization and capture doesn't seem to include things like invoice id as one of the fields it refers to in the documentation. There must be some way to do this. Help? (I'm using a JSON implementation, not an XML one). I see an itemID under "line items" in the Try It example, is that where I should put the invoice id?
