Hello. I have a program that takes a letter of the alphabet and translates it to a number on a telephone key pad. Everything is correct and prints out great in the console, but I need to do a GUI version of it, and I'm having massive trouble trying to figure out what the code is for the char user input.
I've tried to put in things like 

userLetter = Parse.charParse (
        JOptionPane.showInputDialog("Please enter letter...");

but it's not working, and I have no other clue what it could be. The console version is below, I just need help with what I need to change the
"char userLetter =(QWERTY.next()).charAt(0);" to in order to get a GUI input box version. I know how to change the rest. Thanks in advance!

import java.util.Scanner;
import javax.swing.JOptionPane;
public class Letter {
 
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Scanner QWERTY = new Scanner(System.in);
		System.out.println("Enter a letter of the alphabet to see what number it corresponds to.");
 
 
		char userLetter =(QWERTY.next()).charAt(0);
 
		char letter = 0;
		letter = (char) Character.toUpperCase(userLetter);
 
		int Digit = 0;
 
			if (letter == 'A' || letter == 'B' || letter == 'C') {
			Digit = 2;
			}
 
			else if (letter == 'D' || letter == 'E' || letter == 'F') {
				Digit = 3;
			}
 
			else if (letter == 'G' || letter == 'H' || letter == 'I') {
				Digit = 4;
			}
 
			else if (letter == 'J' || letter == 'K' || letter == 'L') {
				Digit = 5;
			}
 
			else if (letter == 'M' || letter == 'N' || letter == 'O') {
				Digit = 6;
			}
 
			else if (letter == 'P' || letter == 'Q' || letter == 'R' || letter == 'S') {
				Digit = 7;
			}
 
			else if (letter == 'T' || letter == 'U' || letter == 'V') {
				Digit = 8;
			}
 
			else if (letter == 'W' || letter == 'X' || letter == 'Y' || letter == 'Z') {
				Digit = 9;
			}
 
 
		if (Digit==1 || Digit==2 || Digit==3 || Digit==4 || Digit==5 || Digit==6 || +
				Digit==7 || Digit==8|| Digit==9) {
 
			System.out.println("The corresponding number is = " + Digit);
		}
 
		else {
			System.err.println("Error. Please try again.");
		}
 
	}
 
}