I found my problem, thanks to Reedbeta.
The messages mean the compiler doesn't know what 'command' or 'South' are. You need to define these. If they are already defined they might not be in the right scope. Post your code and I can be more specific.
(By the way, posting code is almost always necessary when asking about a compiler error. You can save time by just posting it up front rather than waiting for someone to ask for it.)