Haha… ok…
Thanks for the reply @emre
I do search about update ticket calculation and found:
Which is the answer to one of my question. However can I know how to auto add the 5% Servicing charge ? Not by have to manually go to "settle and then press the “Service” button and then “Print Bill”?
Can I automate it and then if I want to remove the servicing charge I can press the button instead?