Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button1.Click
        Dim filename As String, filterstring As String = "TXT (*.txt)|*.txt"
        With CD
 
            .Title = "TXT Öffnen"
            .Filter = filterstring
            .ShowDialog()
            filename = .FileName
 
        End With
 
        If filename = "" Then
            Exit Sub
 
        Else
 
        FileCopy(filename, filename.Replace(".txt", "1.txt"))
        TextBox1.Text = filename  
        End If