A tutor sent me this code but it is not working for me. Can some please tell me whats wrong with the code.

String sideA, sideB;

sideA=txt_sidea.getText();

sideB=txt_sideb.getText();

Double hypotenuse;

if(!sideA.isEmpty() && !sideB.isEmpty())

{

try

{

//find the square root of (side1^2 + side2^2)

hypotenuse = Math.sqrt(Math.pow(Double.parseDouble(sideA), 2) + Math.pow(Double.parseDouble(sideB), 2));

txt_sidec.setText(hypotenuse.toString());

}

catch(Exception ex)

{

JOptionPane.showMessageDialog(null,"Side A must be a number Side B must be a number", "Invalid data", JOptionPane.ERROR_MESSAGE);

}

}

else

{

JOptionPane.showMessageDialog(null,"Enter Side A and Side B", "Invalid data", JOptionPane.ERROR_MESSAGE);

}

The whole code is below

Explanation:

import javax.swing.JOptionPane;

public class mainForm extends javax.swing.JFrame {

public mainForm() {

initComponents();

}

@SuppressWarnings("unchecked")

//

private void initComponents() {

txt_sidea = new javax.swing.JTextField();

txt_sideb = new javax.swing.JTextField();

txt_sidec = new javax.swing.JTextField();

jLabel1 = new javax.swing.JLabel();

jLabel2 = new javax.swing.JLabel();

jLabel3 = new javax.swing.JLabel();

btn_calc = new javax.swing.JButton();

btn_exit = new javax.swing.JButton();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

jLabel1.setText("Side A");

jLabel2.setText("Side B");

jLabel3.setText("Side C");

btn_calc.setText("Calculate");

btn_calc.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent evt) {

btn_calcActionPerformed(evt);

}

});

btn_exit.setText("Exit");

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());

getContentPane().setLayout(layout);

layout.setHorizontalGroup(

layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()

.addGap(50, 50, 50)

.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

.addComponent(jLabel1)

.addComponent(jLabel2)

The question is

i need help with creat ing a GUI for an that lets the user calculate the hypotenuse of a right triangle.

The GUI with valid data

\fE Eric-l Invalid Data Side A must be a valid number. Side B must be a valid number