What would be a very simple coding solution to question 9 on page 538 in textbook Starting Out with Visual C# 4th edition, by Tony Gaddis? I am looking for very basic/elementary level C# coding used for Windows Form App. Any guidance would be greatly appreciated.

Question states:

Alphabetic Telephone Number Translator - Many companies use telephone numbers like 555-GET-FOOD so the number is easier for the customers to remember. On a standard telephone, the alphabetic letters are mapped to numbers in the following fashion (ABC = 2, DEF = 3, GHI = 4, JKL = 5, MNO = 6, PQRS = 7, TUV = 8, WXYZ = 9).

* Create an application that lets the user enter a 10-character telephone number in the format xxx-xxx-xxxx. The application should display the telephone number with any alphabetic characters that appeared in the original translated to their numeric equivalent. For example, if the user enters 555-GET-FOOD, the application should display 555-438-3663.