Describe the step-by-step process to THIS sequence diagram :

- step 1 : dentify a set of objects that will participate in the general collaboration

- step 2 : Consider the first point of the scenario

- step 3 : Consider what the system needs to be done to respond to an actor when the actor sends the message to the system

- step 4 : Repeat each of the points of the scenario (or flow of event) and until you complete all the points in the scenario

CUSTOMER EMPLOYEE GENERATE BILL DATABASE ADD FEW ITEMS SCAN BARCODE FOR PR CE RETURN PRICE AND DESCRIPTION CALCULATE TOTAL AMOUNT PASS THE BILL ASK FOR PAYMENT SELECT RANK ACCOUNT FOR PAYMENT PASS THE TRANSACTION PROCEED FOR CHECKOUT BILL GENERATED WITH DISSCOUNT AND TOTAL PRICE DATABASE UPDATED CHECKS AMOUNT CORRECT AS PER ADDED ITEMS