file close or overwrite

 
 static void Main(string[] args)
        {
            string date =  DateTime.Now.ToString("yyyyMMddhhmmss");

            /* FileMode.OpenOrCreate so the file will be saved! 
               The date isn't necessary, but i don't want the overwrite the file */

            FileStream fs = new FileStream("test" + date + ".CSV", FileMode.OpenOrCreate);

            /* also you can using FileMode.Append if the file already exist and you want 
               to append text into the file without overwrite  */

            StreamWriter fso = new StreamWriter(fs);

            /* Write something to the file */
            for (int i = 0; i < 100; i++)
            {
                fso.WriteLine(i);
            }
            /* Save the file */
            fso.Flush();
        }