title: FocusListener on JTextField not working
body: <p>I've created an application that uses FocusListener to make sure a text fieid's value is always positive. When the user inputs negative value and then click the "tab" key to move focus away from the text field, the value will be multiplied by -1 so that the resulted value is positive. However, when I ran the application, the text field didn't change. I am not sure what I did wrong, and will appreciate any help.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>import java.awt.event.*;
  import javax.swing.*;
  import java.awt.*;
  
  public class AlwaysPositive extends JFrame implements FocusListener {
  JTextField posField = new JTextField("30",5);
  
  public AlwaysPositive() {
      super("AlwaysPositive");
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      JPanel pane = new JPanel();
      JTextField posField = new JTextField("30",5);
      JButton ok= new JButton("ok");
      posField.addFocusListener(this);
      pane.add(posField);
      pane.add(ok);
      add(pane);
      setVisible(true);
  }
  
  public void focusLost(FocusEvent event) {
      try {
          float pos = Float.parseFloat(posField.getText());
          if (pos &lt; 0) 
              pos = pos*-1;
          posField.setText("" + pos);
      } catch (NumberFormatException nfe) {
          posField.setText("0");
      }
  }
  
  public void focusGained(FocusEvent event) {
  }
  
  public static void main(String[] arguments) {
      AlwaysPositive ap = new AlwaysPositive();
  }
  </code></pre>
  
  <p>}</p>