If you are using the Enfold WordPress theme, it is likely that you'll need to make modifications to its main script avia.js. This is how you can safely copy the avia.js file to your child theme and make modifications.

enfold_child_script

/* enqueue child script if not in dashboard */

if (!(is_admin())) {
  function change_aviajs() {
    wp_enqueue_script( 'avia-default-child', get_stylesheet_directory_uri().'/js/avia.js', array('jquery'), 2, true );
  }
  add_action( 'wp_print_scripts', 'change_aviajs', 100 );
}

/* dequeue child script */

function dequeue_aviajs() {
   wp_dequeue_script( 'avia-default' );
}
add_action( 'wp_print_scripts', 'dequeue_aviajs', 100 );