ElseIf ComboBox1.Text = "Turbine Data" Then
            'start of first combo box code
            Dim filepath As String = My.Application.Info.DirectoryPath & turbdatxml
 
            If Dir(filepath) <> "" Then
 
                If (TextBox1.Text.Equals("") Or TextBox2.Text.Equals("") Or TextBox3.Text.Equals("") Or TextBox4.Text.Equals("")) Then
 
                    MsgBox(val_txt, , inval_title)
 
                Else
                    Dim ExistingData As New MyDatum
 
                    Dim Serializer As New System.Xml.Serialization.XmlSerializer(GetType(MyDatum))
 
                    If (File.Exists(filepath)) Then '& Not EOF(1)
 
                        'Need to find out how to check End of File, and skip this bit of code if file is empty
 
                        Dim OpenStream As System.IO.FileStream = System.IO.File.Open(filepath, IO.FileMode.Open)
 
                        'Protects existing data, to make a list, rather than overwriting data.
                        ExistingData = Serializer.Deserialize(OpenStream)
 
                        OpenStream.Close()
                    Else
 
                        MsgBox(cre05, , err05)
 
                    End If
 
                    Dim NewData As New MyData
 
                    TextBox1.Focus()
                    NewData.DateStamp = CDate(Date.Today()) 'DateValue(Now)
                    NewData.TimeStamp = CDate(TimeString())
                    'find out how to display the date and time seperate, not as a stamp
                    NewData.Gap = gaptext.Text
                    NewData.Diameter = diatext.Text
                    NewData.R2 = TextBox1.Text
                    NewData.VentDiamater = TextBox2.Text
                    NewData.R1 = TextBox3.Text
                    NewData.Height = TextBox4.Text
 
                    ExistingData.Add(NewData)
 
                    Dim SaveStream As System.IO.FileStream = System.IO.File.Open(filepath, IO.FileMode.Open)
                    ' IO.FileMode.Create or .Open
 
                    Serializer.Serialize(SaveStream, ExistingData)
 
                    SaveStream.Close()
 
                    MsgBox("Data Saved to " & filepath, , _save)
 
                End If
 
            Else
 
                MsgBox(cre05, , err05)
 
                Dim ExistingData As New MyDatum
                Dim Serializer As New System.Xml.Serialization.XmlSerializer(GetType(MyDatum))
                Dim NewData As New MyData
                Dim SaveStream As System.IO.FileStream = System.IO.File.Open(filepath, IO.FileMode.Create)
 
                TextBox1.Focus()
                NewData.DateStamp = CDate(Date.Today()) 'DateValue(Now)
                NewData.TimeStamp = CDate(TimeString())
                NewData.Gap = gaptext.Text
                NewData.Diameter = diatext.Text
                NewData.R2 = TextBox1.Text
                NewData.VentDiamater = TextBox2.Text
                NewData.R1 = TextBox3.Text
                NewData.Height = TextBox4.Text
 
                Serializer.Serialize(SaveStream, ExistingData)
                SaveStream.Close()
            End If
            'End of first combo box code

Dim doc as New  System.Xml.XmlDocument()
doc.Load("file.xml") 'Load an XML document
...
...
doc.Save("file.xml") 'Save the document