Private Sub WriteXmlToFile(thisDataSet As DataSet)
    If thisDataSet Is Nothing Then
        Return
    End If
 
    ' Create a file name to write to.
    Dim filename As String = "XmlDoc.xml"
 
    ' Create the FileStream to write with.
    Dim stream As New System.IO.FileStream _
       (filename, System.IO.FileMode.Create)
 
    ' Create an XmlTextWriter with the fileStream.
    Dim xmlWriter As New System.Xml.XmlTextWriter _
       (stream, System.Text.Encoding.Unicode)
 
    ' Write to the file with the WriteXml method.
    thisDataSet.WriteXml(xmlWriter)
    xmlWriter.Close()
End Sub