'Dokumente zusammenfügen durch Auswahl der Dokumente
    '##########################################################################
    ' ##########################################################
    Private Sub chkFile1_CheckedChanged(ByVal sender As System.Object, ByVal e _
      As System.EventArgs) Handles chkFile1.CheckedChanged
        Me.txtFile1.Enabled = Me.chkFile1.Checked
        Me.cmdFile1.Enabled = Me.chkFile1.Checked
        txtFile1.BackColor = Color.White
    End Sub
 
    Private Sub chkFile2_CheckedChanged(ByVal sender As System.Object, ByVal e _
      As System.EventArgs) Handles chkFile2.CheckedChanged
        Me.txtFile2.Enabled = Me.chkFile2.Checked
        Me.cmdFile2.Enabled = Me.chkFile2.Checked
    End Sub
 
    Private Sub chkFile3_CheckedChanged(ByVal sender As System.Object, ByVal e _
      As System.EventArgs) Handles chkFile3.CheckedChanged
        Me.txtFile3.Enabled = Me.chkFile3.Checked
        Me.cmdFile3.Enabled = Me.chkFile3.Checked
    End Sub
 
    Private Sub File_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles cmdFile1.Click, cmdFile2.Click, cmdFile3.Click
 
        Dim btn As Button = CType(sender, Button)
 
        Dim dlg As New OpenFileDialog
        With dlg
            .Title = "PDF auswählen"
            .Filter = "(*.pdf)|*.pdf"
            If .ShowDialog = Windows.Forms.DialogResult.OK Then
                Select Case btn.Name.ToLower
                    Case "cmdfile1"
                        Me.txtFile1.Text = .FileName
                    Case "cmdfile2"
                        Me.txtFile2.Text = .FileName
                    Case "cmdfile3"
                        Me.txtFile3.Text = .FileName
                End Select
            End If
        End With
        dlg.Dispose()
 
    End Sub