need help - access violation - fstream

Im not sure what I'm doing wrong with this bit of code, just reading from one file, writing to another

Debuggin in VC 6.0 get these errors during run time:

First-chance exception in FunctionCalls.exe: 0xC0000005: Access Violation.
The thread 0x884 has exited with code -1073741819 (0xC0000005).
The program 'C:\Documents and Settings\Shana\Desktop\FunctionCalls\Debug\FunctionCalls.exe' has exited with code -1073741819 (0xC0000005).


#include <iostream>
#include <fstream>
#include <string>
using namespace std;

void txtStats(ifstream & in, ofstream & out);
void initalizeArray(int a[], int n);



int main()
{
      ifstream myFile ("example.txt");
      ofstream myData ("data.txt");


      if (myFile.is_open() && myData.is_open())
      {
            txtStats(myFile, myData);

            myFile.close();
            myData.close();
      }


      return 0;
}


void txtStats(ifstream & in, ofstream & out)
{
      int characterFequency[26];
      initalizeArray(characterFequency, 26);

      string word=""; //will hold one line of the file at a time
      int index=0; //will represent the index of the character in the array


      //scan the file word by word and count the number of accourances in the array

      while (! in.eof() )
    {

        in >> word;
        //check each character in the word
        for(int i=0; i< word.length() ; i++)
        {
            if(word[i] >='A' || word[i] <='Z')
                  index = word[i] - 'A';
            else
                  index = word[i] - 'a';

            characterFequency[index]++; //add one to the frequency of this character

        }

      }
        
      //output the results which are contained in the array to the output file called out

      for(int j=0; j< 26; j++)
      {
            char c = j+'a';
            out << c << "\t"<< characterFequency[j] <<"\n";
      }
}

void initalizeArray(int a[], int n)
{
      for(int i=0; i<n; i++)
            a[i]=0;
}