Silverstripe Register Form

// REGISTER FORM
public function RegisterForm()
{
    // Fields
    $fields = new FieldList(
        new TextField('Email', 'Email Address', '', 75),
        new PasswordField('Password'),
        new PasswordField('ConfirmPassword', 'Confirm Password'),
        new TextField('FirstName', 'First Name', '', 50),
        new TextField('LastName', 'Surname', '', 50),
        new DateField('Birthdate', 'Birthday')
    );

    // Actions
    $actions = new FieldList(
        new FormAction('doRegister', 'Submit')
    );

    // Validator
    $validator = new RequiredFields('Email', 'Password', 'ConfirmPassword', 'FirstName', 'LastName', 'Birthdate');

    // Return form
    return new Form($this, 'RegisterForm', $fields, $actions, $validator);
}

// POST REGISTER FORM
public function doRegister( $data, $form )
{
    // Validate form
    die( var_dump($data) );
}