Thread: Pythagorean theorem java applet problem

im not sure whats wrong with my code but i need help fixing it. I need to get the hypotenuse of sides a and b and i am having problems in the code.

// The "Components" class.
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
 
public class ButtonDemo extends JFrame implements ActionListener
{
    // Declare objects
    JLabel label;
    JLabel label2;
    JButton button1, button2;
    JTextField text;
    JTextField text2;
 
    public ButtonDemo ()
    {
        super ("ButtonDemo");
 
        // Set up the frame
        this.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
        this.setBounds (300, 300, 200, 350);
        // Create objects
        JPanel content = new JPanel();
        label = new JLabel ("10",JLabel.CENTER);
        label2 = new JLabel ("20",JLabel.CENTER);
        text = new JTextField (10);
        text2 = new JTextField (10);
        button1 = new JButton ("Calculate");
        button2 = new JButton ("Done");
 
        // Add contents
        content.add (label);
        content.add (label2);
        content.add (button1);
        content.add (button2);
        content.add (text);
        content.add (text2);
 
        // Add listeners
        button1.addActionListener (this);
        button2.addActionListener (this);
        text.addActionListener (this);
 
        // Show the contents
        this.setContentPane (content);
        this.setVisible (true);
    }
 
    public void actionPerformed (ActionEvent e)
    {
        if (e.getSource () == button1)
        {
            a = Double.parseDouble (text1.getText());
        }
        double a = Math.sqrt(a*a+b*b);
        {
            a = 0;		// just make it zero for simplicity
        }
        {
            b= Double.parseDouble (text1.getText());
        }
        double b = Math.sqrt(a*a+b*b);
        {
            b = 0;		// just make it zero for simplicity
        }
        double c = Math.sqrt(a*a+b*b);
        {
            label.setText ("The hyp is:" + c);
        }
    }
    else if (e.getSource () == button2)
    {
        label.setText ("Exit.");
        System.exit(0);
 
    }
 
} // main method
} // Components class