Public Class cIo
    Private Shared m_File as string
    Public Shared Property File as string 
        Get
            return m_File
        End Get
        Set(Value as string)
            if io.File.Exists(Value) then
                m_File = value
            else
                m_File = ""
                Throw new Ex("die datei " & Value & " wurde nicht gefunden")
            end if
        End Set
    End Property
End class