Code java

Bonjour,
j'ai un code java pour afficher un message d'erreur , mais ce code dans une package qui contien plusieur class.
alors
1-comment fait pour executer ce programme seul ( donner moi le code correcte )? .
2-Quel est le rôle de initcomponents() ?

package ead;

public class ERREUR extends javax.swing.JFrame {

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

/** 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.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
private void initComponents() {

jDialog1 = new javax.swing.JDialog();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();

javax.swing.GroupLayout jDialog1Layout = new javax.swing.GroupLayout(jDialog1.getContentPane());
jDialog1.getContentPane().setLayout(jDialog1Layout);
jDialog1Layout.setHorizontalGroup(
jDialog1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
);
jDialog1Layout.setVerticalGroup(
jDialog1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 300, Short.MAX_VALUE)
);

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("Erreur!!");

jLabel2.setFont(new java.awt.Font("Times New Roman", 1, 12)); // NOI18N
jLabel2.setForeground(new java.awt.Color(255, 0, 0));
jLabel2.setText("Attention vous avez marqué un erreur!!");

jLabel3.setFont(new java.awt.Font("Times New Roman", 3, 14)); // NOI18N
jLabel3.setForeground(new java.awt.Color(255, 0, 0));
jLabel3.setIcon(new javax.swing.ImageIcon("C:\\tf\\GIF's\\32X32\\info.gif")); // NOI18N
jLabel3.setText("Verifier");

jButton1.setIcon(new javax.swing.ImageIcon("C:\\tf\\GIF's\\24X24\\cancel.gif")); // NOI18N
jButton1.setText("Fermer");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(136, 136, 136)
.addComponent(jLabel2))
.addGroup(layout.createSequentialGroup()
.addGap(163, 163, 163)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jButton1)
.addComponent(jLabel3))))
.addContainerGap(210, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(52, 52, 52)
.addComponent(jLabel2)
.addGap(18, 18, 18)
.addComponent(jLabel3)
.addGap(18, 18, 18)
.addComponent(jButton1)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);

pack();
}// </editor-fold>//GEN-END:initComponents

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
// TODO add your handling code here:

ERREUR AA=new ERREUR();
this.dispose();
}//GEN-LAST:event_jButton1ActionPerformed

/**
* @param args the command line arguments
*/


// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JButton jButton1;
private javax.swing.JDialog jDialog1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
// End of variables declaration//GEN-END:variables

}



merci d'avnace