What the heck am I doing wrong???

Question

The error message I'm getting is the following: "week4_herbie must be defined in its own file" The problem that I'm running into is that the programs are supposed to work together. One (week4_herbie) handles the mortgage calculation itself (and set up the GUI) and send the information to the amoritizeFrame program, which is designed to display the amoritization table. The numericTextFrame is to make sure that the variable input is acceptable. Here is the coding:
week4_herbie
The Amortization Schedule was constructed with my own class called AmortFrame
that extends JFrame and a JTextArea that was added to a JScrollPane.
// Imports needed libraries
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
// Event handling:implements listener interface for receiving action events.
public class week4_herbie implements ActionListener
     // GUI Components
     JFrame calculatorFrame;
     JPanel calculatorPanel;
     AmortizeFrame amortFrame;   //local class for amortization schedule
     //  user input fields
     //  Loan amount entered as user text input from keyboard
     //  Term (in years) selected from a combo box
     //  Rate (%) selected from a combo box
     numericTextField loan;
     JComboBox rate;
     JComboBox term;
     // set up arrays for the selectable term and rate
    int[] loanTerm = new int[3];
    String[] loanTermString = new String[3];
    double[] loanRate = new double[3];
    String[] loanRateString = new String[3];
    // static variables, belong to class on not an instance
     static String sWindowTitle = "Brian's Week 3 - Mortgage Calculator";
     static String scolHeader = "Payment#\tPayment\tInterest\tCumInterest\tPrincipal\tBalance\n";
     static String slineOut = "________\t_______\t________\t___________\t_________\t_______\n";
     static String sfinalInstructions1 = "\nYou can leave windows open and enter new value or close either window to exit\n";
     JLabel loanLabel,termLabel, rateLabel, pmtLabel;
     JButton calculate;
    public week4_herbie()
          // Before progressing, read in the data
          if(readData())
               //Create and set up the window.
               calculatorFrame = new JFrame(sWindowTitle);
               calculatorFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               // Set size of user input frame;
               calculatorFrame.setBounds(0,0,100,100);
               //Create and set up the panel with 4 rows and 4 columns.
               calculatorPanel = new JPanel(new GridLayout(4, 4));
               //Add the widgets.
               addWidgets();
               //Set the default button.
               calculatorFrame.getRootPane().setDefaultButton(calculate);
               //Add the panel to the window.
               calculatorFrame.getContentPane().add(calculatorPanel, BorderLayout.
               CENTER);
               //Display the window.
               calculatorFrame.pack();
               calculatorFrame.setVisible(true);
          }// good data read
    }// end constructor
    private boolean readData()
          boolean isValid = true;
        loanRateString[0] = "5.35%";
        loanRateString[1] = "5.5%";
        loanRateString[2] = "5.75%";
        loanTermString[0] = "7 Years";
        loanTermString[1] = "15 Years";
        loanTermString[2] = "30 Years";
        loanRate[0] = 5.35;
        loanRate[1] = 5.5;
        loanRate[2] = 5.75;
        loanTerm[0] = 7;
        loanTerm[1] = 15;
        loanTerm[2] = 30;
        return isValid;
     }// end readData
    // Creates and adds the widgets to the user input frame.
    private void addWidgets()
        // numericTextField is a JTextField with some error checking for
        // non  numeric values.
        loan = new numericTextField();
        rate = new JComboBox(loanRateString);
          term = new JComboBox(loanTermString);
        loanLabel = new JLabel("Loan Amount", SwingConstants.LEFT);
        termLabel = new JLabel(" Term ", SwingConstants.LEFT);
        rateLabel = new JLabel("  Interest Rate ", SwingConstants.LEFT);
        calculate = new JButton("Calculate");
        pmtLabel  = new JLabel("Monthly Payment", SwingConstants.LEFT);
        //Listen to events from the Calculate button.
        calculate.addActionListener(this);
        //Add the widgets to the container.
        calculatorPanel.add(loan);
        calculatorPanel.add(loanLabel);
        calculatorPanel.add(term);
        calculatorPanel.add(termLabel);
        calculatorPanel.add(rate);
        calculatorPanel.add(rateLabel);
        calculatorPanel.add(calculate);
        calculatorPanel.add(pmtLabel);
        //set label border size
        loanLabel.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
        pmtLabel.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
    } // end addWidgets
    // Event handling method invoked when an action occurs.
    // Processes each of the fields and includes error checking
    // to make sure each field has data in it and then calculates
    // actual payment.
    public void actionPerformed(ActionEvent event)
        double tamount = 0; //provides floating point for total amount of the loan
        int term1      = 0; //provides int for the term
        double rate1   = 0; //provides floating point for the percentage rate.
        // get string to test that user entered
            String testit = loan.getText();          // get user entered loan amount
            // if string is present
            if(testit.length() != 0)
               tamount = (double)(Double.parseDouble(testit)); // convert to double
               // first value valid - check second one, term value
               // get the index of the item the user selected
               // then get the actual value of the selection from the
               // loanTerm array
               int boxIndex = term.getSelectedIndex();
               if(boxIndex != -1)
                    term1 = loanTerm[boxIndex];
                    // second value valid - check third one, interest rate
                    // get the index of the item the user selected
                   // then get the actual value of the selection from the
                   // loanRate array
                   boxIndex = rate.getSelectedIndex();
                   // if something is selected in rate combo box
                    if(boxIndex != -1)
                        rate1 = loanRate[boxIndex];
                         // all three values were good so calculate the payment
                    double payment = ((tamount * (rate1/1200)) /
                                          (1 - Math.pow(1 + rate1/1200, -term1*12)));
                    // format string using a mask
                    java.text.DecimalFormat dec = new java.text.DecimalFormat(",###.00");
                    String pmt = dec.format(payment);
                    // change foreground color of font for this label
                    pmtLabel.setForeground(Color.green); //
                    // set formatted payment
                         pmtLabel.setText(pmt);
                         // generate the amortization schedule
                         amortize(tamount, rate1*.01, term1*12, payment);
                    else  //third value was bad
                         Toolkit.getDefaultToolkit().beep(); // invokes audible beep
                         pmtLabel.setForeground(Color.red);  // sets font color
                         pmtLabel.setText("Missing Field or bad value");  // Error Message
                    }// end validate third value
               else  // second value was bad
                    Toolkit.getDefaultToolkit().beep();
                    pmtLabel.setForeground(Color.red);
                    pmtLabel.setText("Missing Field or bad value");
               }// end validate second value
          else  // first value was bad
               Toolkit.getDefaultToolkit().beep();
               pmtLabel.setForeground(Color.red);
             pmtLabel.setText("Missing Field or bad value");
          }// end validate first value
    }// end actionPerformed
     // calculate the loan balance and interest paid for each payment over the
     // term of the loan and list it in a separate window - one line per payment.
     public void amortize(double principal, double APR, int term,
                          double monthlyPayment)
          double monthlyInterestRate = APR / 12;
          //double totalPayment = monthlyPayment * term;
          int payment = 1;
          double balance = principal;
          int num = 0;
          double monthlyInterest;
          double cumInterest = 0;
        // if the frame for the amortization schedule has not been created
        // yet, create it.
          if(amortFrame == null)
             amortFrame = new AmortizeFrame();
          // obtain a reference to our text area in our frame
          // and update this as we go through
          JTextArea amortText = amortFrame.getAmortText();
          // formatting mask
          java.text.DecimalFormat df= new java.text.DecimalFormat(",###.00");
          // set column header
          amortText.setText(scolHeader);
          amortText.append(slineOut);
          // loop through our amortization table and add to
          // JTextArea
          while(num < term)
               monthlyInterest = monthlyInterestRate * balance;
               cumInterest += monthlyInterest;
               principal = monthlyPayment - monthlyInterest;
               balance -= principal;
               //Show Amortization Schedule
               amortText.append(String.valueOf(payment));
               amortText.append("\t ");
               amortText.append(df.format(monthlyPayment));
               amortText.append("\t ");
               amortText.append(df.format(monthlyInterest));
               amortText.append("\t ");
               amortText.append(df.format(cumInterest));
               amortText.append("\t ");
               amortText.append(df.format(principal));
               amortText.append("\t ");
               amortText.append(df.format(balance));
               amortText.append("\n");
               payment++;
               num++;
          // print the headers one more time at the bottom
          amortText.append(slineOut);
          amortText.append(scolHeader);
          amortText.append(sfinalInstructions1);
     }// end amortize
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
    private static void createAndShowGUI()
        //Make sure we have nice window decorations.
         //Note this next line only works with JDK 1.4 and higher
        JFrame.setDefaultLookAndFeelDecorated(true);
        week4_herbie calculator = new week4_herbie();
    // main method
    public static void main(String[] args)
         // allow user to set a different file from
         // command line
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable()
            public void run()
                createAndShowGUI();
}// end classAmoritizeFrame
import java.awt.*;
import javax.swing.*;
// this class provides the frame and the scrolling text area for the
// amortization schedule
class AmortizeFrame extends JFrame
     private JTextArea amortText;
     private JScrollPane amortScroll;
     private String sTitle = "Brian's";
     final String sTitle2 = " Amortization Schedule";
     // default constructor
     public AmortizeFrame()
          initWindow();
     // constructor that takes parameter (such as week number)
     // to add extra info to title on frame of window
     public AmortizeFrame(String week)
          sTitle = sTitle + " " + week;
          initWindow();
     }// end constructor
     // helper method that initialized GUI
     private void initWindow()
          setTitle(sTitle + sTitle2);
          setBounds(200,200,550,400);
          Container contentPane=getContentPane();
          amortText = new JTextArea(7,100);
          amortScroll= new JScrollPane(amortText);
          contentPane.add(amortScroll,BorderLayout.CENTER);
          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          setVisible(true);
     // method to get the text area for users of
     // this frame.  They can then add whatever text they want from the outside
     public JTextArea getAmortText()
          return amortText;
}// end amortizeFramenumericTextFrame
* This is a control that subclasses the
* JTextField class and through a keyboard
* listener only allows numeric input, decimal point
* and backspace into the text field.
* Known Problems!!!:
* 1) It will not catch if the user
*    enters two decimal points
import java.awt.Toolkit;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.JTextField;
   A JTextField subclass component that
   only allowing numeric input.  
class numericTextField extends JTextField
    private void setUpListener()
        addKeyListener(new KeyAdapter() {
            public void keyTyped(KeyEvent e)
                        char c = e.getKeyChar();
                if(!Character.isDigit(c) && c != '.' && c != '\b' && c != '\n' && c != '\177')
                    Toolkit.getDefaultToolkit().beep();
                    e.consume();
    numericTextField(int i)
         super(i);
           setUpListener();
    public numericTextField()
          setUpListener();
}Thanks for the assist

Answer 1

Top-level classes (that is, classes not inside other classes) must be defined as public or package-private (the default access level if you do not provide one).
A public top-level class Foo must be contained in Foo.java.
A non-public top-level class Foo can be contained in any .java file.