Your subdomain will be active after 10 minutes.The administration as well as the current status of your subdomains can be found at my.world4you.com under Your package > Domains > Subdomains.
Important: Only access your subdomain after 10 minutes, otherwise your computer will assume that the subdomain does not exist and will remember this.It will then take up to an hour before your computer checks the existence of your subdomain again and you can access your subdomain.