Palindrome assignment for Android Apprentice class

This program allows a user to enter a word and then checks to see if the word entered is a palindrome. It uses four methods, including the main method that starts the program. Methods are called to check if the user has entered letters only. The another method is called to reverse the word. Then another method is called to check if the word is a palindrome. It then returns the answer. If only letters are entered the program will loop allowing the user to enter more words. If a non-letter character is entered the game stops.