I need help making table show an amortize table. What am I doing wrong? Would appreciate any feedback. Need it tonight, if possible. Trying to learn on my own. This is homework

Code:
import java.text.NumberFormat;

/*Robin Williams
 * PRG/421
 * Week 3, Change Request 5
 * GUI for Mortgage Calculator with Array/Menu
 */

 
public class MortgageCalculatorJFrame extends javax.swing.JFrame {

    /** Creates new form MortgageCalculatorJFrame */
    public MortgageCalculatorJFrame() {
        initComponents();
    }
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        loanAmountLbl = new javax.swing.JLabel();
        loanChoiceLbl = new javax.swing.JLabel();
        loanAmountTxt = new javax.swing.JTextField();
        loanChoiceCmb = new javax.swing.JComboBox();
        calculateButton = new javax.swing.JButton();
        clearButton = new javax.swing.JButton();
        quitButton = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        resultsTxtArea = new javax.swing.JTextArea();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        loanAmountLbl.setText("Loan Amount");

        loanChoiceLbl.setText("Loan Choice");

        loanChoiceCmb.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "7 years at 5.35%", "15 years at 5.5%", "30 years at 5.75%" }));
        loanChoiceCmb.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                loanChoiceCmbActionPerformed(evt);
            }
        });

        calculateButton.setText("Calculate");
        calculateButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                calculateButtonActionPerformed(evt);
            }
        });

        clearButton.setText("Clear");
        clearButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                clearButtonActionPerformed(evt);
            }
        });

        quitButton.setText("Quit");
        quitButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                quitButtonActionPerformed(evt);
            }
        });

        resultsTxtArea.setColumns(20);
        resultsTxtArea.setRows(5);
        jScrollPane1.setViewportView(resultsTxtArea);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(72, 72, 72)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(loanAmountLbl, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(loanChoiceLbl, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addGap(86, 86, 86)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(loanAmountTxt, javax.swing.GroupLayout.DEFAULT_SIZE, 230, Short.MAX_VALUE)
                            .addComponent(loanChoiceCmb, javax.swing.GroupLayout.Alignment.TRAILING, 0, 230, Short.MAX_VALUE)))
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                        .addComponent(clearButton, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(100, 100, 100)
                        .addComponent(quitButton, javax.swing.GroupLayout.PREFERRED_SIZE, 86, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addGap(54, 54, 54))
            .addGroup(layout.createSequentialGroup()
                .addGap(28, 28, 28)
                .addComponent(calculateButton)
                .addContainerGap(377, Short.MAX_VALUE))
            .addGroup(layout.createSequentialGroup()
                .addGap(55, 55, 55)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 377, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(50, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(47, 47, 47)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(loanAmountLbl, javax.swing.GroupLayout.PREFERRED_SIZE, 23, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(loanAmountTxt, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(59, 59, 59)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(loanChoiceLbl, javax.swing.GroupLayout.PREFERRED_SIZE, 23, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(loanChoiceCmb, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(29, 29, 29)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(calculateButton)
                    .addComponent(quitButton)
                    .addComponent(clearButton))
                .addGap(34, 34, 34)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 134, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(23, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void loanChoiceCmbActionPerformed(java.awt.event.ActionEvent evt) {                                              
        
    }                                             

    @SuppressWarnings("empty-statement")
    private void calculateButtonActionPerformed(java.awt.event.ActionEvent evt) {                                                

        double dblPrincipal = (Double.parseDouble (loanAmountTxt.getText()));                  //principal amount
        double [] dblInterestRate = {5.35,5.5,5.75};     //intialized the array with values(interest rate)
        int []intLoanTermYear  = {7,15,30};              //intialized the array with values(loan term)
        double [] dblMonthlyPayment = {0,0,0};            //intialized the array with zero values(monthly payment)
        double [] dblMonthlyInterestRate= {0,0,0};        //intialized the array with zero values(monthly interest rate)
        int [] intLoanTermMonth = {0,0,0};               //intialized the array with zero values(loan term in months)
        int box = loanChoiceCmb.getSelectedIndex();
        double dblcurrentbalance = 0;
        double dblcurrentmonthlyPrincipalpayment = 0;
        double dblcurrentmonthlyInterestpaid = 0;
        double dblcurrentmonthlyprincipal = 0;
        double dblpreviousmonthlybalance = 0;

        {

            dblMonthlyInterestRate[box] = dblInterestRate[box]/(12 * 100); //calculate monthly interest rate per array


            intLoanTermMonth[box] = intLoanTermYear[box] * 12;             //calculate number of months of loan

            /* Monthlypayment formula using array index values */
            dblMonthlyPayment[box] = dblPrincipal * ( dblMonthlyInterestRate[box] / (1 - (Math.pow((1 + dblMonthlyInterestRate[box]),-(intLoanTermMonth[box])))));

            /* Calculation formulas*/
                dblcurrentmonthlyInterestpaid = (dblPrincipal * dblMonthlyInterestRate[box]);          //current monthly interest
                dblcurrentmonthlyPrincipalpayment = (dblMonthlyPayment[box] - dblMonthlyInterestRate[box]); //current monthlt principal payment
                dblcurrentmonthlyprincipal = (dblPrincipal - dblcurrentbalance);                               //calculate the new balance
                dblpreviousmonthlybalance =  dblcurrentmonthlyprincipal;


                int intlinecounter=1;

                for(intlinecounter=1; intlinecounter<=intLoanTermMonth[box]; intlinecounter++)
                {
               // Formulas to perform calculations
                  dblMonthlyInterestRate[box] = dblpreviousmonthlybalance * dblMonthlyInterestRate[box];
                  dblcurrentbalance = dblMonthlyPayment[box] - dblcurrentmonthlyInterestpaid;
                  dblcurrentmonthlyprincipal = dblpreviousmonthlybalance - dblcurrentbalance;
                  dblpreviousmonthlybalance = dblcurrentmonthlyprincipal;

//Print out Monthly Payment Amount
            NumberFormat CurrencyFormat = NumberFormat.getCurrencyInstance();
resultsTxtArea.append("The Loan Principal is " +(CurrencyFormat.format (dblPrincipal))+ "." + "\n"+"The loan's interest rate is" +""+"" + dblInterestRate[box] +"%." + "\n"+"The loan term is"+""+intLoanTermYear[box]+""+ "years."+"\n"+"The monthly payment will be"+""+(CurrencyFormat.format (dblMonthlyPayment[box])));

           if(intlinecounter % 20 == 0)
{              intlinecounter=1;
               System.out.println("Press any key to continue");
                                try
                                {  System.in.read();
                                }catch (Exception e){;
                                        }
            
            
            
        }
                }}
    }                                               
    private void quitButtonActionPerformed(java.awt.event.ActionEvent evt) {                                           
       System.exit(0);
    }                                          

    private void clearButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            
        loanAmountTxt.setText(null);
        loanChoiceCmb.setSelectedIndex(-1);
        resultsTxtArea.setText(null);
    }                                           

    /**
    * @param args the command line arguments
    */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new MortgageCalculatorJFrame().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton calculateButton;
    private javax.swing.JButton clearButton;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JLabel loanAmountLbl;
    private javax.swing.JTextField loanAmountTxt;
    private javax.swing.JComboBox loanChoiceCmb;
    private javax.swing.JLabel loanChoiceLbl;
    private javax.swing.JButton quitButton;
    private javax.swing.JTextArea resultsTxtArea;
    // End of variables declaration                   

}