I can not get my calculator to calculate at all. please help me. thank you


Code:
package mortgagecalculator;


import java.awt.*;
import java.awt.event.*;

import java.util.*;

import javax.swing.*;
import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;
import java.text.DecimalFormat;

import java.text.NumberFormat;
import java.math.*;

import java.awt.BorderLayout;
import java.awt.Color;

import java.awt.Container;
import java.awt.FlowLayout;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JComboBox;

import javax.swing.JCheckBox;
import javax.swing.JFrame;

import javax.swing.JPanel;
import javax.swing.JTextArea;

import javax.swing.JTextField;

import javax.swing.JComboBox;
import javax.swing.JFrame;





public class MortgageCalculator {

double amount;
double term;
double payments;
double amortize;
double interestRateMonths;
double monthlyInterestPayment;
double monthlyPrincipalPayment;
int termMonths;
double balance;
int Labels;


// Instance Variables
JLabel amountLabl, termLabl, IntrateLabl, paymentsLabl, amortizeLab1;
JTextField amountTxf, termTxf, intrateTxf, paymentsTxf, amortizeTxf;
JButton calcBtn;
JButton clearButton;
JButton exitButton;
JFrame frame;
JComboBox Cbox;




public MortgageCalculator() {
  System.out.println("Mortgage Calculator.");

     String Labels[] = { "7 Years at 5.35%", "15 years at 5.5%", "30 years at 5.75%",};


amountLabl = new JLabel("  Loan Amount In Whole Dollars");
termLabl = new JLabel("  Terms In Years");
IntrateLabl = new JLabel("  Interest Rate - Decimal Format (0.000)");
paymentsLabl = new JLabel("  Monthly Payment Amount");

    amountTxf = new JTextField();
      JComboBox cBox1 = new JComboBox(Labels);

    Cbox = new JComboBox(Labels);




termTxf = new JTextField();
intrateTxf = new JTextField();

amortizeTxf = new JTextField();
amortizeLab1 = new JLabel("Amortization");
paymentsTxf = new JTextField();
calcBtn = new JButton("Calculate");
clearButton = new JButton("Clear");
exitButton = new JButton("Exit");



frame = new JFrame("Mortgage Calculator");
frame.setLayout(new GridLayout(16,16));
frame.add(amountLabl);
frame.add(amountTxf);
frame.add(cBox1);


/* Remove these frames when action listener is working  */
  frame.add(termLabl);
  frame.add(termTxf);
  frame.add(IntrateLabl);
  frame.add(intrateTxf);

  

frame.add(paymentsLabl);
frame.add(paymentsTxf);


//  Added amortize textfield and label
frame.add(amortizeLab1);
frame.add(amortizeTxf);

frame.add(calcBtn);
frame.add(clearButton);
frame.add(exitButton);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
clearButton.addActionListener(new Handler());
calcBtn.addActionListener(new Handler());
exitButton.addActionListener(new Handler());
frame.setLocation(300, 300);
frame.pack();
frame.setVisible(true);
}
private class Handler implements ActionListener
{
public void actionPerformed(ActionEvent event)
{


Object command = event.getSource();
if(command == calcBtn)
        {
          calculate();
          }
if(command == clearButton)
        {

          amountTxf.setText(null);
          termTxf.setText(null);
          intrateTxf.setText(null);
          paymentsTxf.setText(null);
             amortizeTxf.setText(null);

            }

            if(command == exitButton)
            {
          System.exit(0);


}
}
}

  public static void main(String[] args) {
  new MortgageCalculator();
}

private void calculate() {
DecimalFormat decimalPlaces=new DecimalFormat("0,000.00");


    String Labels = (String) Cbox.getSelectedItem();

   if (Labels.equals("7 years at 5.35%"))
            {
                double amount1 = Double.parseDouble(amountTxf.getText());
                int    years = 7;
                int    months = (years * 12);
                double    interest    = .0535;
                     double  termMonth = months;
                   double  terms = 7;

            double payments = (amount * ((interest/12) / (1-Math.pow((1+(interest/12)),-(term*12)))));

                paymentsTxf.setText("" + decimalPlaces.format(payments));

            }
     if (Labels.equals("15 years at 5.5%"))
            {
                double amount2 = Double.parseDouble(amountTxf.getText());
                int    years = 15;
                int    months = (years * 12);
                double    interest    = .055;
                     double termMonth = months;
                     double terms = 15;

        double payments = (amount * ((interest/12) / (1-Math.pow((1+(interest/12)),-(term*12)))));

            paymentsTxf.setText("" + decimalPlaces.format(payments));
            }
    if (Labels.equals("30 years at 5.75%"))
            {
                double amount3 = Double.parseDouble(amountTxf.getText());
                int    years = 30;
                int    months = (years * 12);
                double    interest    = .0575;
                     double termMonth = months;
                     double terms = 15;

        double payments = (amount * ((interest/12) / (1-Math.pow((1+(interest/12)),-(term*12)))));
         paymentsTxf.setText("" + decimalPlaces.format(payments));

        }

/* This is the area for the amortization process */



// displays monthly mortgage payment resulting from above calculation
        System.out.println("\n\nBased on the above criteria, "  +
         "your monthly payment will be: " +
          "$" + decimalPlaces.format(payments));

    // formula(s) to calculate monthly interest and principal payments
        monthlyInterestPayment = (amount * interestRateMonths);
        monthlyPrincipalPayment = (payments - monthlyInterestPayment);


    // start while loop
  while(termMonths > 0);


  //  {


    // information to display
    System.out.println(termMonths + "\t\t$" + decimalPlaces.format(monthlyPrincipalPayment) +
        "\t\t$" + decimalPlaces.format(monthlyInterestPayment) +
        "\t\t$" + decimalPlaces.format(amount));

    // decrement months
        termMonths--;

    // calculate interest and principal payments
    monthlyInterestPayment = (amount * interestRateMonths);
    monthlyPrincipalPayment = (payments - monthlyInterestPayment);
    balance = (payments - monthlyPrincipalPayment);

     System.out.println(balance);

/**/

     /* Put amortization into a Jtextarea */

     //payments - principal show each payment


}}