Implement a function SSN() Python 3.4.1

Implement a function SSN() which allows the user to enter the Social Security Numbers of employees at a company by name (do not use real data for testing!). The program will keep prompting the user for a name. If the employee does not have a SSN on record,
the program will then ask for the SSN, and store that information. If the employee already has a SSN, the program will display it, and ask for confirmation whether a new SSN should be assigned (and, if so, allows a new SSN to be entered). When the user enters
returns, the program prints a report listing all employees with their SSN.