Settiing error delimiters in config/form_validation.php

Hi,

How to set error delimiters in config/form_validation.php file. I tried this way but it doesnot work

PHP Code:

$config = array(
    
    'membership_form' => array(
        'error_prefix' => '<div class="has-error">',
        'error_suffix' => '</div>',
        array(
            'field' => 'member_name',
            'label' => 'Ad',
            'rules' => 'trim|required'
            ),
        array(
            'field' => 'member_surname',
            'label' => 'Soyad',
            'rules' => 'trim|required'
            ),
        array(
            'field' => 'member_phone',
            'label' => 'Kamu Telefon',
            'rules' => 'trim|min_length[10]|max_length[13]'
            ),
        array(
            'field' => 'member_email',
            'label' => 'Mail Adres',
            'rules' => 'required|valid_email|is_unique_email'
            ),
        array(
            'field' => 'member_password',
            'label' => 'Şifre',
            'rules' => 'trim|required|matches[member_password2]'
            ),
        array(
            'field' => 'member_password2',
            'label' => 'Şifre',
            'rules' => 'trim|required'
            ),
        array(
            'field' => 'lg_remember',
            'label' => 'Gizlilik Sözleşmesi',
            'rules' => 'required' 
            ) ,
        array(
            'field' => 'recaptcha_response_field',
            'label' => 'Güvenlik kodu',
            'rules' => 'required|is_valid_captcha[recaptcha_challenge_field]' 
            ) 
        )
    );