I guess
IPN[
^] will help you to get the
Transaction ID
.
Go to the bottom of the article (Section:- "
A Sample IPN Message and Response").
Quote:
An IPN message consists of variables that describe the transaction. These variables contain information about you, your customer, and the details of the transaction itself.
Information about the transaction:
test_ipn = 1 Testing with the Sandbox
transaction_subject =
txn_id = 61E67681CH3238416 Keep this ID to avoid processing the
transaction twice
txn_type = express_checkout Type of transaction
Also look at the
CodeProject Article on
PayPal Explaining
IPN[
^]