title: Magento: how to get Paypal transaction ID?
body: <p>I'm trying to print the Paypal transaction ID on our invoice PDF files. Can you pull this information from <code>$order</code>, which is an instance of Sales_Order?</p>
  
  <p>I did find some database tables with paypal_ prefix, but all of them are empty, even though we have a real Paypal transaction order in our installation. Any ideas?</p>