8 T U V 4 G H I 9 W X Y Z If the digit entered is not one of the valid digits or one of the valid letters , return – 1 by value indicating that you have an invalid digit . A phone number never begins with a 0 , so the program should flag an error if such a number is entered . Make ReadDials () return – 2 in this case . A phone number never begins with 555 , so the program should flag an error if such a number is entered . Make ReadDials () return – 3 in this case . A phone number always has a hyphen ( - ) in the 4th position . Make ReadDials () return – 4 in this case ( if it doesn ' t have a hyphen in the 4th position ). If a hyphen is in any other position , it is considered an invalid digit . If the phone number is valid , the main calls the AcknowledgeCall function to write the converted number to the output file . All the logic of the program should be put in functions that are called from Main (): ReadDials () and AcknowledgeCall (). The ToDigits () function is called from the ReadDials () function and is used to convert each letter entered individually into a digit and to verify that the user has entered a valid phone number . Have the program work for any number of phone numbers . In the ToDigits () function uses the toupper function to convert any letters entered to uppercase . All the error messages are to be written to the output file from main () based on the return value from the functions . Continue processing until the user enters a Q . You will set up the 8 char variables to hold the digits of the phone number in main () and pass the variables to the functions by reference . Sample Output from the Program Enter a phone number ( Q to quit ): 213-2121 Phone Number Dialed : 213-2121 Enter a phone number ( Q to quit ): asc-dfer Phone Number Dialed : 272-3337 Enter a phone number ( Q to quit ): 555-resw ERROR - Phone number cannot begin with 555 Enter a phone number ( Q to quit ): 098-8765 ERROR - Phone number cannot begin with 0 Enter a phone number ( Q to quit ): 12345678 ERROR - Hyphen is not in the correct position Enter a phone number ( Q to quit ): @ 34- * uyt ERROR - An invalid character was entered Enter a phone number ( Q to quit ): Q Press any key to continue . . . Step 2 : Processing Logic Using the pseudocode below , write the code that will meet the requirements .