private void jTextField2ActionPerformed(java.awt.event.ActionEvent evt) {
    String LastName = "last name: "+jTextField2.getText();
}

private void jTextField3ActionPerformed(java.awt.event.ActionEvent evt) {
    String UserName = "user name: "+jTextField3.getText();
}

private void jTextField4ActionPerformed(java.awt.event.ActionEvent evt) {
    String password = "password: "+jTextField4.getText();
}

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
    JOptionPane.showMessageDialog(null,"name: "+name);         //error cant ac
    JOptionPane.showMessageDialog(null,"last name: "+LastName);//error cant access
    JOptionPane.showMessageDialog(null,"user name: "+UserName);//error cant access
    JOptionPane.showMessageDialog(null,"password : "+password);//error cant access
}