Problems implementing comboboxes and having the program work

Question

import java.text.DecimalFormat; //class for format decimals
import java.awt.*;
import javax.swing.*;
import java.applet.Applet;
import java.awt.event.*;
public class MortgageCal2 extends JApplet {
JLabel principal_Label;
JLabel interestRate_Label;
JLabel termYear_Label;
JTextField principal_TF;
JTextField interestRate_TF;
JComboBox interestRate_CB;
JTextField termYear_TF;
JComboBox termYear_CB;
JButton calculate_button;
JButton clear_button;
JLabel monthlyPI_Label;
JLabel payment_Label;
//*********************Main Program for MortgageCal2 Class***************************
public static void main(String[] args) {
     JFrame calculator = new JFrame();
     MortgageCal2 calc = new MortgageCal2();
     calculator.getContentPane().add(calc);
     calc.init();
     calculator.pack();
     calculator.setVisible(true);               
public void init() {
     MortgageCalLayout customLayout = new MortgageCalLayout();
     Container con1 = getContentPane();
     con1.setLayout(customLayout);
     principal_Label = new JLabel("PRINCIPAL:");//1
          con1.add(principal_Label);
     interestRate_Label = new JLabel("INTEREST RATE:");//2
          con1.add(interestRate_Label);
     termYear_Label = new JLabel("TERM YEARS:");//3
          con1.add(termYear_Label);
     principal_TF = new JTextField();//4
          con1.add(principal_TF);
          interestRate_TF = new JTextField();//5
          con1.add(interestRate_TF);
          String[] interestArray = {"5.35", "5.50", "5.75"};
          interestRate_CB = new JComboBox(interestArray);
          termYear_TF = new JTextField();//6
          con1.add(termYear_TF);
          String[] termArray = {"7", "15", "30"};
          termYear_CB = new JComboBox (termArray);
          JButton calculate_button = new JButton("CALCULATE");//7
          con1.add(calculate_button);
     monthlyPI_Label = new JLabel("MONTHLY P&I: ");//8
          con1.add(monthlyPI_Label);
     JButton clear_button = new JButton("CLEAR");//9
          con1.add(clear_button);
     payment_Label = new JLabel();
          con1.add(payment_Label);
          if (termYear_CB.getSelectedItem().equals ("7"))
               interestRate_CB.setSelectedIndex(1);
                    else if(termYear_CB.getSelectedItem().equals ("15"))
               interestRate_CB.setSelectedIndex(2);
                    else if(termYear_CB.getSelectedItem().equals ("30"))
               interestRate_CB.setSelectedIndex(0);
     //********Listener for Interest Rate ComboBox***********************
     interestRate_CB.addItemListener(new ItemListener(){
          public void itemStateChanged(ItemEvent ev)
          int idx=interestRate_CB.getSelectedIndex();
          termYear_CB.setSelectedIndex(idx);
     //*********Listener for Calculate Button*****************************
     calculate_button.addActionListener(
          new ActionListener() {
public void actionPerformed(ActionEvent h) {
//***********************Decimal Format**************************
java.text.DecimalFormat DF = new DecimalFormat("###,###.00");
//***************Variables***************************************
double principal = Double.parseDouble(principal_TF.getText());
double interestRate = Double.parseDouble(interestRate_TF.getText());
double monthlyInterest;
double termYear = Double.parseDouble(termYear_TF.getText());
double termMonthly;
double monthlyPI;
//*****************Calculations************************************
monthlyInterest = interestRate / 12 / 100;
termMonthly = termYear * 12;
monthlyPI = (principal * monthlyInterest) / (1 - Math.pow(1 + monthlyInterest, -termMonthly));
//*****************Displays Payment***********************************
payment_Label.setText("$" + DF.format(monthlyPI));
//***************Listener for Clear Button************************
clear_button.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent h) {
principal_TF.setText("");
interestRate_TF.setText("");
termYear_TF.setText("");
payment_Label.setText("");
class MortgageCalLayout implements LayoutManager {
     //***********Constructor for the MortgageCal Layout object*************************
     public MortgageCalLayout() { }
     //********Adds a feature to the LayoutComponent attribute for the MortgageCal Layout object**********
     public void addLayoutComponent(String name, Component comp) {
     //**************Method description************************
public void removeLayoutComponent(Component comp) {
     public Dimension preferredLayoutSize(Container parent) {
          Dimension dim = new Dimension(0, 0);
          Insets insets = parent.getInsets();
     dim.width = 250 + insets.left + insets.right;
     dim.height = 250 + insets.top + insets.bottom;
return dim;
     public Dimension minimumLayoutSize(Container parent) {
     Dimension dim = new Dimension(0, 0);
return dim;
     public void layoutContainer(Container parent) {
     Insets insets = parent.getInsets();
     Component c;
     c = parent.getComponent(0);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 20, insets.top + 10, 100, 25);
     c = parent.getComponent(1);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 20, insets.top + 40, 100, 25);
     c = parent.getComponent(2);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 20, insets.top + 72, 100, 25);
     c = parent.getComponent(3);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 115, insets.top + 10, 115, 25);
     c = parent.getComponent(4);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 115, insets.top + 40, 115, 25);
     c = parent.getComponent(5);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 115, insets.top + 75, 115, 25);
     c = parent.getComponent(6);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 115, insets.top + 105, 115, 25);
     c = parent.getComponent(7);
               if (c.isVisible()) {
                    c.setBounds(insets.left + 20, insets.top + 140, 100, 25);
     c = parent.getComponent(8);
          if (c.isVisible()) {
          c.setBounds(insets.left + 115, insets.top + 200, 120, 25);
     c = parent.getComponent(9);
          if (c.isVisible()) {
          c.setBounds(insets.left + 115, insets.top + 140, 75, 25);

Answer 1

import java.text.DecimalFormat; //class for format decimals
import java.awt.*;
import javax.swing.*;
import java.applet.Applet;
import java.awt.event.*;
public class MortgageCal2 extends JApplet {
JLabel principal_Label;
JLabel interestRate_Label;
JLabel termYear_Label;
JTextField principal_TF;
JTextField interestRate_TF;
JComboBox interestRate_CB;
JTextField termYear_TF;
JComboBox termYear_CB;
JButton calculate_button;
JButton clear_button;
JLabel monthlyPI_Label;
JLabel payment_Label;
//*********************Main Program for MortgageCal2 Class***************************
public static void main(String[] args) {
     JFrame calculator = new JFrame();
     MortgageCal2 calc = new MortgageCal2();
     calculator.getContentPane().add(calc);
     calc.init();
     calculator.pack();
     calculator.setVisible(true);               
public void init() {
     MortgageCalLayout customLayout = new MortgageCalLayout();
     Container con1 = getContentPane();
     con1.setLayout(customLayout);
     principal_Label = new JLabel("PRINCIPAL:");//1
          con1.add(principal_Label);
     interestRate_Label = new JLabel("INTEREST RATE:");//2
          con1.add(interestRate_Label);
     termYear_Label = new JLabel("TERM YEARS:");//3
          con1.add(termYear_Label);
     principal_TF = new JTextField();//4
          con1.add(principal_TF);
          interestRate_TF = new JTextField();//5
          con1.add(interestRate_TF);
          String[] interestArray = {"5.35", "5.50", "5.75"};
          interestRate_CB = new JComboBox(interestArray);
          termYear_TF = new JTextField();//6
          con1.add(termYear_TF);
          String[] termArray = {"7", "15", "30"};
          termYear_CB = new JComboBox (termArray);
          JButton calculate_button = new JButton("CALCULATE");//7
          con1.add(calculate_button);
     monthlyPI_Label = new JLabel("MONTHLY P&I: ");//8
          con1.add(monthlyPI_Label);
     JButton clear_button = new JButton("CLEAR");//9
          con1.add(clear_button);
     payment_Label = new JLabel();
          con1.add(payment_Label);
          if (termYear_CB.getSelectedItem().equals ("7"))
               interestRate_CB.setSelectedIndex(1);
                    else if(termYear_CB.getSelectedItem().equals ("15"))
               interestRate_CB.setSelectedIndex(2);
                    else if(termYear_CB.getSelectedItem().equals ("30"))
               interestRate_CB.setSelectedIndex(0);
     //********Listener for Interest Rate ComboBox***********************
     interestRate_CB.addItemListener(new ItemListener(){
          public void itemStateChanged(ItemEvent ev)
          int idx=interestRate_CB.getSelectedIndex();
          termYear_CB.setSelectedIndex(idx);
     //*********Listener for Calculate Button*****************************
     calculate_button.addActionListener(
          new ActionListener() {
public void actionPerformed(ActionEvent h) {
//***********************Decimal Format**************************
java.text.DecimalFormat DF = new DecimalFormat("###,###.00");
//***************Variables***************************************
double principal = Double.parseDouble(principal_TF.getText());
double interestRate = Double.parseDouble(interestRate_CB.getText());
double monthlyInterest;
double termYear = Double.parseDouble(termYear_CB.getText());
double termMonthly;
double monthlyPI;
//*****************Calculations************************************
monthlyInterest = interestRate / 12 / 100;
termMonthly = termYear * 12;
monthlyPI = (principal * monthlyInterest) / (1 - Math.pow(1 + monthlyInterest, -termMonthly));
//*****************Displays Payment***********************************
payment_Label.setText("$" + DF.format(monthlyPI));
//***************Listener for Clear Button************************
clear_button.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent h) {
principal_TF.setText("");
interestRate_TF.setText("");
termYear_TF.setText("");
payment_Label.setText("");
class MortgageCalLayout implements LayoutManager {
     //***********Constructor for the MortgageCal Layout object*************************
     public MortgageCalLayout() { }
     //********Adds a feature to the LayoutComponent attribute for the MortgageCal Layout object**********
     public void addLayoutComponent(String name, Component comp) {
     //**************Method description************************
public void removeLayoutComponent(Component comp) {
     public Dimension preferredLayoutSize(Container parent) {
          Dimension dim = new Dimension(0, 0);
          Insets insets = parent.getInsets();
     dim.width = 250 + insets.left + insets.right;
     dim.height = 250 + insets.top + insets.bottom;
return dim;
     public Dimension minimumLayoutSize(Container parent) {
     Dimension dim = new Dimension(0, 0);
return dim;
     public void layoutContainer(Container parent) {
     Insets insets = parent.getInsets();
     Component c;
     c = parent.getComponent(0);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 20, insets.top + 10, 100, 25);
     c = parent.getComponent(1);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 20, insets.top + 40, 100, 25);
     c = parent.getComponent(2);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 20, insets.top + 72, 100, 25);
     c = parent.getComponent(3);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 115, insets.top + 10, 115, 25);
     c = parent.getComponent(4);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 115, insets.top + 40, 115, 25);
     c = parent.getComponent(5);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 115, insets.top + 75, 115, 25);
     c = parent.getComponent(6);
          if (c.isVisible()) {
                    c.setBounds(insets.left + 115, insets.top + 105, 115, 25);
     c = parent.getComponent(7);
               if (c.isVisible()) {
                    c.setBounds(insets.left + 20, insets.top + 140, 100, 25);
     c = parent.getComponent(8);
          if (c.isVisible()) {
          c.setBounds(insets.left + 115, insets.top + 200, 120, 25);
     c = parent.getComponent(9);
          if (c.isVisible()) {
          c.setBounds(insets.left + 115, insets.top + 140, 75, 25);
MortgageCal2.java:122: cannot resolve symbol
symbol : method getText ()
location: class javax.swing.JComboBox
double interestRate = Double.parseDouble(interestRate_CB.getText());
^
MortgageCal2.java:124: cannot resolve symbol
symbol : method getText ()
location: class javax.swing.JComboBox
double termYear = Double.parseDouble(termYear_CB.getText());
Everything worked until I added the combo boxes. Now I get these errors.