creating a SaveFileDialog

private void button1_Click(object sender, System.EventArgs e)
{
  Stream myStream ;
  SaveFileDialog saveFileDialog1 = new SaveFileDialog();

  saveFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"  ;
  saveFileDialog1.FilterIndex = 2 ;
  saveFileDialog1.RestoreDirectory = true ;

  if(saveFileDialog1.ShowDialog() == DialogResult.OK)
  {
      if((myStream = saveFileDialog1.OpenFile()) != null)
      {
          // Code to write the stream goes here.
          myStream.Close();
      }
  }
}