I don't know about abacre - but i think for most cashiers who are not owner-users - the onus shouldn't be on the user (a cashier) to check/uncheck this option. I ,as a owner of the business, should be able to lock down this feature. i.e. the cashier should not have the option to check/uncheck the FTP-ing process.
If i locked it down - the end-of-day should silently go ahead with the transmission of sales data.
ADDITIONALLY, the uploaded sales data should contain the order-no as well. If all the sales record is going to be transmitted - it is imperative the unique order-no be included as well.
what do you think?