ecart receipt with bar code
I'm building a site that the client wants the eCart receipt to generate a custom ID (number) or some sort of a bar code. This receipt will be used for online event ticket sales so each receipt # cannot be duplicated. Best example would be: You purchase a ticket online for an upcoming event, you print your receipt and bring it to the event as your ticket and proof of purchase.
I would greatly appreciate any feedback to how to accomplish creating a custom receipt number or creating some type of bar code in conjunction.