Change $page_security does not change their access

I've created a new role with only "Sales order edition" role. This only let me create orders, but I want to grant access to Inquiry Sales Orders.
So I change the $page_security in sales_orders_view.php with the same value as sales_order_entry.php, but when I log in the Inquiry Order Sales is always disabled.

What am I doing wrong?

Thanks,