what's up with static members?

[Aragorn]

Hi to all of you.

I'm trying to use a static variable in my class which is defined in a header file. The problem is that the linker won't let me do it like this:

Error: Unresolved external 'Cell::Parent' referenced from C:\C++\NETWORK\NNMAIN.OBJ

The class is something like this:

// file: nnetwork.h

class Cell {
private:
   static another_class* Parent;
   //stuff...

public:
   SetParent(another_class*);
   //stuff...
};

which is #included in nnmain.cpp

// file: nnmain.cpp

#include "nnetwork.h"

I would like to know the right way to link many source files into a single executable (no dlls). Maybe i should also know the way to separate the source correctly, because this is not the first time i get this kind of errors (also when using extern) and i don't know how to solve it.

Thanks

[Aragorn]

ops!
sorry, i corrected the error with the explanations on the other thread about "static". However i still get errors when i try to use extern variables.
Could someone give me a brief explanation about linkage scope and available modifiers?
Thank you.