what is the code in VB to get current user logon in windows?

what is the code in VB to get current user logon in windows?
here is the code I am using
Function GetUserName() As String

    If TypeOf My.User.CurrentPrincipal Is Security.Principal.WindowsPrincipal Then

        ' The application is using Windows authentication.

        ' The name format is DOMAIN\USERNAME.

        Dim parts() As String
        parts() = Split(My.User.name, "\")

        Dim username As String
        username = parts(1)

        Return username

    Else

        ' The application is using custom authentication.

        Return My.User.Name

    End If

End Function

'Dim name As String
    'name = My.User.name
    'MsgBox (name)