C++ :: String Array Sorting Into Alphabetical Order

I am trying to read information in from a file, each line of which contains a name in the form 'last, first middle'. I can successfully open the file and read it into an array that is roughly 2500 string in size. The problem comes when I try to sort the array into alphabetical order. I am using a sorting algorithm that we were instructed to use, found in our book. It is shown in the code. I would add the file that needs to be opened, but it is a few thousand lines long.

The error I am getting is:
Unhandled exception at 0x00A28628 in PeopleSearch.exe: 0xC0000005: Access violation reading location 0x00CC400C.

and I know it has to do with the sorting algorithm from using break points and running the program with that section commented out. I am stumped to why it is giving this error, as it seems that it is trying to access the array outside of the bounds of the array, but it shouldn't be

Here is my code:

#include<iostream>
#include<string>
#include<fstream>

using namespace std;
int main() {
string NameArray[2500], filename; //declare array and file to open

[Code] ....