Error Check does not work

Question

Hi, I'm having a problem with the following code, when I add alphabetic characters or even nothing at all in the principal amt text field, I expect to get an error message, but I do not. This happens no matter which method I choose to compute the mortgage.
//Import required libraries
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
import java.io.*;
import java.text.*;
import java.math.*;
import java.util.*;
public class pos407checkbox extends JFrame implements ActionListener
     // implements ActionListener, ItemListener
     NumberFormat formatter = new DecimalFormat ("$###,###.00");
     //Common Variables
     String ErrorMsg;
     double principal;
     double IntRate;
     int Term;
     double monthlypymt;
     double EndBalance =0;
     double FirstEndBalance =0;
     double interestpmt = 0 ;
     double principlepmt = 0;
     int choice = 0;
     //Components for Menu items
     private JMenuBar menuBar;    
     private JMenuItem exitMenuItem; 
     private JMenu fileMenu; 
     //create the common components
     private JPanel jPanelRadioButton = new JPanel();
     private JPanel jPanelActionButtons = new JPanel();
     JRadioButton jRadiochoice1 = new JRadioButton("I want to enter my own principal, rate and term",false);
     JRadioButton jRadiochoice2 = new JRadioButton("I will enter my own principal, and choose rate and term",false);
     private JButton buttonCompute;
     private JButton buttonNew; 
     private JButton buttonClose;
     //create the components required for jRadiochoice1
     private JPanel jPanelUserEnterAllValues = new JPanel();
     private JLabel jLabelMortgageAmt = new JLabel("Principal Amt(No decimals or commas)");
     private JLabel jLabelMortgageAmt2 = new JLabel("Principal Amt(No decimals or commas)");   
     private JLabel jLabelIntRate = new JLabel("Interest Rate"); 
     private JLabel jLabelTerm = new JLabel("Term - In Years"); 
     private JTextField jTextFieldMortgageAmt = new JTextField();
     private JTextField jTextFieldMortgageAmt2 = new JTextField();
     private JTextField jTextFieldIntRate= new JTextField();
     private JTextField jTextFieldTerm = new JTextField();
     //create the components required for jRadiochoice2
     private JPanel jPanelRateAndTermSelection;
     private JLabel jLabelChooseRateAndTerm; 
     private JComboBox TermAndRate;
     //create the output area
     private JPanel jPanelAmoritizationSchedule;
     private JTextArea jTextAreaAmoritization;
     public pos407checkbox() {            
          super("Mortgage Application");      
           initComponents();      
      private void initComponents()
          setSize(800,460);
          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);      
          setVisible(true);           
          Container pane = getContentPane();
          //GridLayout grid = new GridLayout(5, 1);      
          FlowLayout grid = new FlowLayout();      
          pane.setLayout(grid);
          //**********************************MENU BAR**************************//
          menuBar = new JMenuBar();
          fileMenu = new JMenu();
          fileMenu.setText("File");        
          exitMenuItem = new JMenuItem(); 
           exitMenuItem.setText("Exit");
          fileMenu.add(exitMenuItem); 
          menuBar.add(fileMenu);
          //pane.add(menuBar);       
          setJMenuBar(menuBar);
          //*****************************RADIO BUTTON PANEL***************************//
          jPanelRadioButton = new JPanel();
          GridLayout Radio = new GridLayout(1,2);
          jPanelRadioButton.setLayout(Radio);
          ButtonGroup RadioButtons = new ButtonGroup();
          RadioButtons.add(jRadiochoice1);
          RadioButtons.add(jRadiochoice2);
          jPanelRadioButton.add(jRadiochoice1); 
          jPanelRadioButton.add(jRadiochoice2);       
          pane.add(jPanelRadioButton);
          //***********************USER INTERFACE FOR CHOICE 1*******************//
          GridLayout userchoice = new GridLayout(3,2);
          //FlowLayout userchoice = new FlowLayout();           
          jPanelUserEnterAllValues.setLayout(userchoice);
          jPanelUserEnterAllValues.add(jLabelMortgageAmt); 
          jPanelUserEnterAllValues.add(jTextFieldMortgageAmt);       
          jPanelUserEnterAllValues.add(jLabelIntRate);
          jPanelUserEnterAllValues.add(jTextFieldIntRate);       
          jPanelUserEnterAllValues.add(jLabelTerm);
          jPanelUserEnterAllValues.add(jTextFieldTerm); 
          jPanelUserEnterAllValues.setVisible(false);
          pane.add(jPanelUserEnterAllValues);
          //***********************USER INTERFACE FOR CHOICE 2*******************//
          // Create a label that will advise user to enter a principle amount
          jPanelRateAndTermSelection = new JPanel();
          TermAndRate = new JComboBox();
          //Add the selections to the combo box
          TermAndRate.addItem("7 years at 5.35%");
          TermAndRate.addItem("15 years at 5.5%");
          TermAndRate.addItem("30 years at 5.75%");
          //FlowLayout RateAndTerm = new FlowLayout(FlowLayout.CENTER);
          GridLayout RateAndTerm = new GridLayout(2,2);
          jPanelRateAndTermSelection.setLayout(RateAndTerm);
          jPanelRateAndTermSelection.add(jLabelMortgageAmt2);
          jPanelRateAndTermSelection.add(jTextFieldMortgageAmt2);   
          jLabelChooseRateAndTerm = new JLabel("Choose the Rate and Term");
          jPanelRateAndTermSelection.add(jLabelChooseRateAndTerm);
          jPanelRateAndTermSelection.add(TermAndRate);
          jPanelRateAndTermSelection.setVisible(false);
          pane.add(jPanelRateAndTermSelection);
          //------------------THIRD PANEL CHOOSE ACTION----------------------
          jPanelActionButtons = new JPanel();
          buttonCompute = new JButton("Compute Mortgage");
          buttonNew = new JButton("New Mortgage");
          buttonClose = new JButton("Close");
          FlowLayout Actionbuttons = new FlowLayout(FlowLayout.CENTER);
          jPanelActionButtons.setLayout(Actionbuttons);
          jPanelActionButtons.add(buttonCompute);
          jPanelActionButtons.add(buttonNew);
          jPanelActionButtons.add(buttonClose);
          jPanelActionButtons.setVisible(false);
          pane.add(jPanelActionButtons);
          //*******************ADD THE TEXT AREA FOR OUTPUT TO THE GUI******************//
          jPanelAmoritizationSchedule = new JPanel();
          jTextAreaAmoritization = new JTextArea(26,50);
          JScrollPane scrollBar = new JScrollPane(jTextAreaAmoritization, 
          JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
            JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
          scrollBar.setPreferredSize(new Dimension(500,250));
          FlowLayout Amoritization = new FlowLayout();
          jPanelAmoritizationSchedule.setLayout(Amoritization);
          // add scroll pane to output text area
          jPanelAmoritizationSchedule.add(scrollBar);
          jPanelAmoritizationSchedule.setVisible(false);
            pane.add(jPanelAmoritizationSchedule);
          setContentPane(pane);
          //pack();
          // Add Action Listeners
          exitMenuItem.addActionListener(this);
          buttonCompute.addActionListener(this);         
          buttonNew.addActionListener(this);
          buttonClose.addActionListener(this);
          TermAndRate.addActionListener(this);
          jRadiochoice1.addActionListener(this);
          jRadiochoice2.addActionListener(this);
//create a method that will clear all fields when the New Mortgage button is chosen
private void clearFields()
     jRadiochoice1.setSelected(false);
     jRadiochoice2.setSelected(false);
     jTextAreaAmoritization.setText("");
     jPanelAmoritizationSchedule.setVisible(false);
     jPanelActionButtons.setVisible(false);
     jTextFieldMortgageAmt.setText("");
     jTextFieldMortgageAmt2.setText("");
     jPanelRadioButton.setVisible(true);
     jPanelUserEnterAllValues.setVisible(false);
     jPanelRateAndTermSelection.setVisible(false);
  public void actionPerformed(ActionEvent e)
          Object source = e.getSource();  
          if (source == exitMenuItem)
                   System.exit(0);
          if(source == buttonClose)
               System.exit(0);
          if (source == buttonNew)
               clearFields();
          if (source == jRadiochoice1)
               jPanelActionButtons.setVisible(true);
               jPanelRadioButton.setVisible(false);
               jPanelUserEnterAllValues.setVisible(true);
               principal = Double.parseDouble(jTextFieldMortgageAmt.getText());
               choice  = 1;
          }//End if for checkbox1
          if (source == jRadiochoice2)
               jPanelRateAndTermSelection.setVisible(true);
               jPanelAmoritizationSchedule.setVisible(true);
               jPanelActionButtons.setVisible(true);
               jPanelRadioButton.setVisible(false);
               choice = 2;
          if (source == buttonCompute)
               jPanelAmoritizationSchedule.setVisible(true);
               //Make sure the user entered valid numbers for the principal
               if (choice ==2)
                    int[] term = {7,15,30};
                    double[] rate = {5.35,5.50,5.75};
                    try
                         principal = Double.parseDouble(jTextFieldMortgageAmt2.getText());
                    catch(NumberFormatException nfe)
                         ErrorMsg = (" You Entered an invalid Mortgage amount"
                              + " Please try again. Please do not use commas or decimals");
                         jTextAreaAmoritization.setText(ErrorMsg);
                    int loan = TermAndRate.getSelectedIndex();
                    Term = term[loan];
                    IntRate = rate[loan];
               else
                    try
                         principal = Double.parseDouble(jTextFieldMortgageAmt.getText());
                    catch(NumberFormatException nfe)
                         ErrorMsg = (" You Entered an invalid Mortgage amount"
                              + " Please try again. Please do not use commas or decimals");
                         jTextAreaAmoritization.setText(ErrorMsg);
                    try
                         IntRate = Double.parseDouble(jTextFieldIntRate.getText());
                    catch(NumberFormatException nfe)
                         ErrorMsg = (" You entered an invalid Interest Rate");
                         jTextAreaAmoritization.setText(ErrorMsg);
                    try
                         Term = Integer.parseInt(jTextFieldTerm.getText());
                    catch(NumberFormatException nfe)
                         ErrorMsg = (" You entered an invalid Term value");
                         jTextAreaAmoritization.setText(ErrorMsg);
               jTextAreaAmoritization.setText(" Loan amount of " + formatter.format(principal) );
               double intdecimal = intdecimal = IntRate/(12 * 100);
               int months = Term * 12;
               int paymentNum = months;
               double monthlypayment = principal *(intdecimal / (1- Math.pow((1 + intdecimal),-months)));
               //Display the Amoritization schedule header info
               jTextAreaAmoritization.setText(" Loan amount of " + formatter.format(principal)
                                                + "\n"
                                                + " Interest Rate is " +  IntRate + "%"
                                        + "\n"
                                        + " Term in Years "  + Term
                                        + " Monthly payment "+  formatter.format(monthlypayment)
                                        + "\n"
                                        + "  Amoritization is as follows:  "
                                        + "\n"
                                        + "****************************************************************************************************"
                                        + "\n"
                                        + "PAYMENT # " + "\t" + "UNPAIDBALANCE"
                                        + "\t" + "PRINCIPLE PAID" + "\t" + "INTEREST PMT" + "\n\n");
     public static void main(String[]args) { 
          pos407checkbox gui = new pos407checkbox(); 
}

Answer 1

it does actually get set.
the problem is your actionperformed() falls throught to the final
jTextAreaAmoritization.setText(" Loan amount of " + formatter.format(principal) etc etc
at every error handler you need to exit the method
catch()
ErrorMsg = (" You entered an invalid Interest Rate");
jTextAreaAmoritization.setText(ErrorMsg);
return;//<-------------------
}