Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim filename As String = System.Environment.GetEnvironmentVariable( _
        "USERPROFILE") + "\ntuser.dat.LOG"
        Dim res As Boolean = FileIsOpen(filename)
    End Sub
 
    Public Function FileIsOpen(ByVal file As String) As Boolean
        Dim fs As IO.FileStream = Nothing
        Try
            If Not IO.File.Exists(file) Then Return False
            fs = IO.File.OpenWrite(file)
            Return False
        Catch ex As System.IO.IOException
            Debug.WriteLine(ex.ToString)
            Return True
        Finally
            If Not (fs Is Nothing) Then
                fs.Close()
            End If
        End Try
    End Function