The Main Function

the first line should use a function to load the records of SalesPerson.dat into a list of salesperson objects called salesPersonList.

before the program ends, use a function to

to save the records of salesPersonList in SalesPerson.dat as comma separated values $($id$,$ name, city$)$

prompts the user to choose from:

Add Salesperson

Display Salesforce

Add Sales

Display Sales

End Program

Add Salesperson

prompt the user to enter an id$,$ name and city

use a function to ensure the id is not already being used by another record

create a salesperson object based on id$,$ name and city

add the salesperson object to salesPersonList

Display Salesforce

displays the id$,$ name and city of each salesperson on separate lines

the display should be nicely spaced out without commas

Add Sales

prompt the user to enter an id$,$ table sales, desk sales and chair sales

make sure that all sales entered are valid

use another function to ensure that the id exists

adds the sales as a string $($id$,$ tableSales, deskSales, chairSales$)$ in a list called salesList

Display Sales

display the id$,$ table sales, desk sales and chair sales of each salesperson

End Program

the id$,$ name and city of each salesperson will be saved as a comma separate values in SalesPerson.dat