[hardwired]

A pseudo code suggestion:

Code:

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;

public class GQM
{
    public static void main(String[] args)
    {
        JFrame jFrame;
        jFrame = new JFrame();
        JOptionPane.showMessageDialog(jFrame, "This is a Geography Quiz");
        JOptionPane.showMessageDialog(null, "Good Luck");

        char choice;
        int i, choice1;
        String yourChoice;
        int Password;
        String passString;

        passString = JOptionPane.showInputDialog("Enter the Password");

//        Password = passString.nextInt();
        Password = Integer.parseInt(passString);

        if (Password == 123)
        {
            JOptionPane.showMessageDialog(null, "Valid. You typed the right password. " +
                                          "Now choose from the following menu");
            JOptionPane.showMessageDialog(null, "Welcome!\nThis is a Geography Quiz\n" +
                                          "Choose from the following Menu:");


            JOptionPane.showMessageDialog(null, "1. Plate Tectonics\n2. Rivers\n3. Rocks\n4. Quit");

            passString = JOptionPane.showInputDialog("Enter your choice");
            choice1 = Integer.parseInt(passString);

            // Convert variable from string to integer
            if(choice1<1 || choice1>4) 
            {
                JOptionPane.showMessageDialog(null, "This is an invalid choice"); 
            }

            switch(choice1)
            {
                case 1:
                    JOptionPane.showMessageDialog(null,"You are taking the Plate Tectonics Quiz");
                    String s = readFile("plate_tectonics.txt");
                    JOptionPane.showMessageDialog(null, s);
                    // Or you can write this into a JTextArea in your JFrame center section.
            }
        }
        else
        {
            JOptionPane.showMessageDialog(null, "Invalid Password. Try Again");
        }
    }

    private static String readFile(String path)
    {
        Scanner s = null;
        StringBuilder sb = new StringBuilder();
        String separator = " ";  // or "\n"
        try
        {
            s = new Scanner(new BufferedReader(new FileReader(path)));
            s.useDelimiter(",\\s*");
            while (s.hasNext())
            {
                sb.append(s.next(), separator);
//                JOptionPane.showMessageDialog(null,s.next());
            }
        }
        finally
        {
            if (s != null) 
                s.close();
            break;
        }
        return sb.toString();
    }
}