Because you never invoked you
MenuInput method inside
main, so it doesn't get executed.
Also note that you have two else blocks that contain same statements. Instead of it, you could put if - else if - else blocks to check your input. Or, if you use JDK 7 you can use switch statement with Strings, so it would be the best approach to use here. And, instead of invoking
MenuInput again if the user does not provide valid input,
you should put everything inside while, that will prompt the user for input until valid one is entered.
Edit: Method names don't start with capital letter in
Java.