Thread: Need Help with program

Hello all I am kinda new to java I am trying to write a simple program. This program will accept 2 values from the user and calculate the third avue when the user clicks the "Calculate" button. The problem That I am having is that I want to assign an action listener to both of the text fields so that it can listen in on what value the user enters. Since I am using Eclipse it is showing me and error wehn I try to assign action listener to the formated text fields. Can someone please point out to me where I am going wrong. I have'ht written the logic that calculates the two numbers yet. I want to get everything correct in my GUI before I move on to that point. Below is my code so far

import java.awt.*;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
public class SimpleCalculation {
 
           //Fields for data entry
           final JFormattedTextField currentField; 
           final JFormattedTextField systemVoltageField;
 
          //Labels to identify the fields
          final JLabel currentLabel;
          final JLabel systemVoltageLabel;
 
         //The button
         final JButton button;
 
         // begin constructor here
         public SimpleCalculation(){
        JFrame frame;
        JPanel panel;
 
        frame = new JFrame("Sun Stone");
        panel = new JPanel();
 
        // create the button
        button = new JButton("Calculate");
 
       //Create the labels.
       currentLabel = new JLabel("Current");
       systemVoltageLabel = new JLabel("System Voltage");
 
      //Create the text fields
      currentField = new JFormattedTextField();
      systemVoltageField = new JFormattedTextField();
 
      // layout the button
      button.addActionListener(new actionEvent());
      panel.add(button);
      frame.add(panel);
 
     // layout the text fields
     frame.add(currentField);
     frame.add(systemVoltageField);
 
    //Other things
    currentField.addActionListener(1);
    systemVoltageField.addActionListener(1);
 
    // rest of the frame
    frame.setSize(400, 400);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);	
 
}
 
	public static void main(String[] args) {
	SimpleCalculation sc;
	sc = new SimpleCalculation();
	}
 
	public void actionEvent (ActionEvent evt){
 
	}
}

Please help me see where I went wrong. I know that there are many examples that I can put and paste that will do something similar but I want to learn the java language and I learn better when I do it on my own.

Make you class implement ActionListener, then use .addActionListener(this);

Regards,
Chris

For you Hassan
in main method..Take an instance of your class and your program will run successfuly
Or

new YOUR_CLASS_NAME();

Post your updated code and I'll have a look, be sure to use code tags

I resolved all my problems but one. I mounted the button, the labels and the text fields onto the frame. The program compiles fine the layouts are exactly what I want it to be. But the problem is that if I move my mouse cursor over the JFrame the labels and the text fields disappears except the button. Any Idea why it is happening?

Here is the updated code

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
 
public class SimpleCalculation implements ActionListener{
	//Data Labels
 
    //Fields for data entry
	final JFormattedTextField currentField; 
	final JFormattedTextField systemVoltageField;
	final JFormattedTextField kVAField;
 
	//Labels to identify the  fields
    final JLabel currentLabel;
    final JLabel systemVoltageLabel;
    final JLabel kVALabel;
 
    //The button
	JButton button;
 
	// begin constructor here
	public SimpleCalculation(){
	JFrame frame;
 
	frame = new JFrame("Sun Stone");
 
	// create the button and set layout
	button = new JButton("Calculate");
	button.setBounds(new Rectangle(20, 90, 40, 30));
 
	// Create current the label and set layout
    currentLabel = new JLabel("Current");
    currentLabel.setLocation(150,180);
    currentLabel.setSize(50,60);
 
    // Create the current text fields and set layout
    currentField = new JFormattedTextField();
    currentField.setLocation(200, 200);
    currentField.setSize(100,25);
    currentField.setForeground(Color.BLACK);
 
    // Create System Voltage the label and set layout
    systemVoltageLabel = new JLabel("System Voltage");
    systemVoltageLabel.setLocation(350,180);
    systemVoltageLabel.setSize(90,60);
 
    //Create the System Voltage text fields and set layout
    systemVoltageField = new JFormattedTextField();
    systemVoltageField.setLocation(445, 200);
    systemVoltageField.setSize(100,25);
    systemVoltageField.setForeground(Color.BLACK);
 
    // Create kVA the label and set layout
    kVALabel = new JLabel("kVA");
    kVALabel.setLocation(590,180);
    kVALabel.setSize(90,60);
 
    // Create the kVA text fields and set layout
    kVAField = new JFormattedTextField();
    kVAField.setEditable(false);
    kVAField.setLocation(620, 200);
    kVAField.setSize(100,25);
    kVAField.setForeground(Color.red);
 
  	button.addActionListener(this);
 
	currentField.addActionListener(this);
	systemVoltageField.addActionListener(this);	
 
	//Put the panels in this panel, labels on left,
    //text fields on right and the button on the bottom.
	frame.add(currentLabel);
	frame.add(systemVoltageLabel);
	frame.add(kVALabel);
	frame.add(currentField);
	frame.add(systemVoltageField);
	frame.add(kVAField);
	frame.add(button);
 
	// Other frame properties
	frame.setSize(1400,1400);
	frame.setVisible(true);
	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
}
	public void actionPerformed(ActionEvent e) {
		double Current=Double.parseDouble(currentField.getText()); 
		double systemVoltage=Double.parseDouble(systemVoltageField.getText()); 
 
		double kVA;
 
		kVA = (Current*(systemVoltage*Math.sqrt(3)))/1000;
 
	}
 
	public static void main(String[] args) {
		SimpleCalculation sc;
		sc = new SimpleCalculation();
		}
}