compilation problems with static data member

I am getting some problems with compiling the following code.
It gives me the following error. I think its ver staright forward and its just that I am missing something. pls help.

I want to access statis data member which is an array of some other class type.
error message:

CalculateMovieSimilarity.cpp:(.text+0x3ce): undefined reference to `CalculateMovieSimilarity::ifileObject'
CalculateMovieSimilarity.cpp:(.text+0x4a7): undefined reference to `CalculateMovieSimilarity::ifileObject'
CalculateMovieSimilarity.cpp:(.text+0x547): undefined reference to `CalculateMovieSimilarity::ifileObject'
collect2: ld returned 1 exit status


and following is the code snippet

Code:

---

class IndexFileObject
{
    public: int count;
            int referencebytepos;
            int relativebytepos[DATEINTERVALS];

};


class CalculateMovieSimilarity
{
    public: static string indexfilename;
            static IndexFileObject ifileObject[17770];           
            static void createifileObject();

};


void CalculateMovieSimilarity::createifileObject(){

        CalculateMovieSimilarity::ifileObject[moviecount].relativebytepos[index]=atoi(relativebytepos.c_str());
  }

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Do you have an actual instance of that static class data member somewhere in your source file?

Code:

---

CalculateMovieSimilarity::IndexFileObject ifileObject[17770];

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