Thread: comment header (file i/o)

I feel pretty stupid for not being able to figure this out, but:

Code:

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
	int hw_num;
	int month;
	int day;
	ofstream file_out ("test.txt", ios::ate);

	cout << "HW#: ";
	cin >> hw_num;
	cout << "Month: ";
	cin >> month;
	cout << "Day: ";
	cin >> day;

	file_out << "/* xxxxxxxxxxxxxxxxxx            xxxxxxxxxxxx */\n";
	file_out << "/* xxxxxxxxxxxxx               xxxxxxxxxxxxxxxx */\n";
	file_out << "/* HW#: " << hw_num << "                        Date: ";
	file_out << month << "-" << day << "-03     */\n";

	return 0;
}

I have only used file i/o to store settings in the past. I need this program to add information to the beginning of my sources for my homework, but it keeps writing over the whole file.

How do I get it to quit writing over the file?
And how do I make sure it adds the commenting to the beginning?

As always, thanks in advance.