Functions.php in child theme nog working?

Hi Support,

How can I make the child theme functions.php file working in the chilc theme? I did place this code in the functions.php of the child team but then the website doen not work anymore. (see code underneath)

add_filter( ‘avf_title_args’, ‘avf_product_titlee’, 0, 2 );
function avf_product_titlee( $args, $id ) {
if ( is_singular(‘product’) ) { $args[‘title’] = get_the_title($id); }
return $args;
}

When I put the code in the functions.php in the child theme folder I get a HTTP error 500 and tekst that http://www.railcenter.nl does not work. So I’am doing something wrong that is for sure ;-). When I remove the code every works fine again.

Altough for updates it is fine as the functions.php changes stay ‘alive’ after an update.

Please advise.

Thanks,
Willem Eelman