C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace FileMaker
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnCreate_Click(object sender, EventArgs e)
        {
            Stream myStream;
            SaveFileDialog saveFileDialog1 = new SaveFileDialog();

            saveFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
            saveFileDialog1.FilterIndex = 1;
            saveFileDialog1.RestoreDirectory = true;

            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                if ((myStream = saveFileDialog1.OpenFile()) != null)
                {
                    StreamWriter wText = new StreamWriter(myStream);
                    wText.Write("CHEESE");

                    myStream.Close();
                }
            } 
        }
    }
}