Write a program that keeps names and email addresses in a dictionary as key-value pairs.
The program should display a menu that lets the user look up a person's email address, add a new name and email address, change an existing email address, and delete an existing name and email address. The program should pickle* the dictionary and save it to a file when the user exits the program. Each time the program starts, it should retrieve the dictionary from the file and unpickle* it.
You must create and use at least 5 meaningful functions.
display a menu
look up a person's email address
add a new name and email address
change an existing email address
delete an existing name and email address.