why inner class can use outer class function ?

Sir:
    I use NetBeans to add a button listener (e.g. mouseClicked, see below),
but I found one starnge thing is the mouseClicked call the outer class
function "jButton1MouseClicked", why the syntax is ok, where can find the
syntax ? In my memory, inner class just can be used by outer class, why it's
ok to use the private function ?

package javaapplication1;

import javax.swing.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;

public class NewJFrame extends javax.swing.JFrame {

    /** Creates new form NewJFrame */
    public NewJFrame() {
        initComponents();
    }

    public void AddAnother() {
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">
    private void initComponents() {
        jScrollPane1 = new javax.swing.JScrollPane();
        jTable1 = new javax.swing.JTable();
        jButton1 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jButton1.setText("jButton1");
        jButton1.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mouseClicked(java.awt.event.MouseEvent evt) {
                jButton1MouseClicked(evt);
            }
        });

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

    private void jButton1MouseClicked(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
    }

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

    }

    // Variables declaration - do not modify
    private javax.swing.JButton jButton1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTable jTable1;
    // End of variables declaration

}

Regards. Ahan