Form submit handler add call to js function

Hello,
i need to call js function after a form submit, this is my code:

function custom_form_newsletter_form($form, &$form_state)
{
    $form['name'] = array(
        '#type' => 'textfield', 
        '#title' => t('Name'),
        '#size' => 60,
        '#maxlength' => 60,
        '#required' => false, //make this field required
    );

    $form['surname'] = array(
        '#type' => 'textfield', 
        '#title' => t('Surname'),
        '#size' => 60,
        '#maxlength' => 60,
        '#required' => true, //make this field required
    );

    $form['submit_button'] = array(
        '#type' => 'submit',
        '#value' => t('Subscribe')
    );

    $form['#attached']['js'] = array(
        drupal_get_path('module', 'custom_form_newsletter') . '/js/add_newsletter.js',
    );

    return $form;
}

I’m trying to add an inline script inside submit handler, this is my code:


function custom_form_newsletter_form_submit($form, &$form_state)
{
    drupal_add_js('jQuery(document).ready(function () { ajaxCall(); });', 'inline');
    drupal_set_message(t('The form has been submitted.'));

}

But the function is never called, the function is defined in ‘/js/add_newsletter.js’,
can anyone help me, please?

Drupal version: 


Source: https://www.drupal.org/taxonomy/term/4/feed