A network administrator wants to change the frequency of their wireless network to allow more channels that do not interfere with
each other. Which of the following frequencies or protocols would accomplish this?
5 GHz
802.119
802.11b
2.4 GHz

Write a program that asks the user to enter the name of an input file. if the file does not exist, the program should prompt the user to enter the file name again. if the user types quit in any uppercase/lowercase combinations, then the program should exit without any further output.