For Each fi In IO.Directory.GetFiles("C:\windows")
            Select Case IO.Path.GetExtension(fi)
                Case ".txt"
                    Debug.WriteLine("Ist text")
                Case ".exe"
                    Debug.WriteLine("Ist proggi")
                Case Else
                    Debug.WriteLine("Nix für uns")
            End Select
        Next

Those people who think they know everything are a great annoyance to those of us who do - Isaac Asimov