And to add...It can only be done through debit.
Guests cannot write a check over the amount.
kinda true. there is one exception: Travelers Checks. if the totals is say $60 and they have a $100 travelers check then they get $40 cash back. to process them, afer you press total press k5 other checks and then k2 travelers check. on a side note be very wary about theese, as they are very rarely used and often fraud. a real one is always underwritten by visa, amex, mastercard, or discover. if it is from a bank it will always have that banks logo in a watermark. They usually only come in denominatiins of 50 or 100's anything else is almost always fraud. always look for holograms on the paper,.and as always printed in dull ink if it shines to the light it's fake. if you think its fake deny it and call over a supervisor and ap immediately, especially if they would get an absurd amount of change like $100 or $200 back.