'Kontextmenü "Kopieren"
    Private Sub cmDateTime_Opening(ByVal sender As Object, ByVal e As _
      System.ComponentModel.CancelEventArgs) Handles cmDateTime.Opening
        If cmDateTime.SourceControl.Text = "" Then
            KopierenToolStripMenuItem.Enabled = False
        Else
            KopierenToolStripMenuItem.Enabled = True
        End If
        CType(cmDateTime.SourceControl, TextBox).Copy()
    End Sub