How do I create a Subdomain in Simple Control Panel?

If you've read the instructions at godaddy.com then why are you at this page? I'll guess, you forgot that one step that always gets me, the Document Root, more specifically the correct way of typing it...

For Server name: y
For Document Root: public_html/y

As for Simple Control Panel, its amazing. I just learned recently that it's a property godaddy offering. If the developers are reading this post maybe they could use the same folder drop-down already in "Manage Backups".