File Stream C#

using System;
using System.IO;
using System.Text;
class FSOpenWrite
{
    public static void Main()
    {
        FileStream fs=new FileStream("c:\\Variables.txt", FileMode.Append, FileAccess.Write, FileShare.Write);
        fs.Close();
        StreamWriter sw=new StreamWriter("c:\\Variables.txt", true, Encoding.ASCII);
        string NextLine="This is the appended line.";
        sw.Write(NextLine);
        sw.Close();
    }
}