how can I force the customer to enter a Code for each item that he adds?

[iwashere]

How can I force the customer to add a code into a text box for each item that he orders. Each item has to have a code entered with it.

if the customer orders 3 of the same items I need 3 codes

example 1 ticket CODE: AABB
1 Ticket CODE: EBFD
1 Ticket CODE: FRHY

The customer already has this code from a previous transaction, but he has to enter it.

Any help would be much appreciated.

v1.3.9h