Linux/C++ system call problem

Hi,

Why doesn't the following C++ program echo the value of 97? If you
manually "head -3 temp.txt | tail -1" the temp.txt file, you will get
97. Use it in a system call, and it doesn't work.

#include <fstream>

using std::fstream;
using std::ios;

int main()
{
int i = 0;
fstream myfile;
myfile.open ("temp.txt", ios::out);
while (i < 100)
	{myfile << i << "\n";
	i++;
	}
system ("echo Third last line of file is:");
system ("tail -3 temp.txt | head -1");
}


Thanks.