Input a unique ref code or cust name for each transaction

[johnnychopsticks]

Is it possible with either the cash register software or this retail software to input a simple 4 or 5 digit number or the customers first name and then complete the transaction/ take money etc..?
My reason for this is that i want to be able to track the transaction perhaps one week to a month later in case their was a problem with the tickets sold etc (we want to use the software in a travel shop).
The number I want to input is the ticket number sold to the customer on the day, and if a problem arises I want to input this ticket number to the system in order to search and find which of my staff has sold the ticket.
Thank you.