You have logged yourself out. You need to log on with a CLERK button. If you have it setup by code, then you need to type a CLERK code and press the CLERK button. Otherwise, just press CLERK1 button.
If you need to change clerk logons, there is a manual here:
manual preview
http://the-checkout-tech.com/manuals/cashregisters/samsung1.php
full manual
http://the-checkout-tech.com/estore/catalog/advanced_search_result.php?keywords=4940&x=0&y=0
Mark, January 2010