Private Sub cmdOK_Click()
Dim iRow As Integer
Dim sDays As String
For iRow = 1 To 7
If lstWeekdays.Selected(iRow - 1) = False Then
sDays = sDays & lstWeekdays.List(iRow - 1) & vbLf
End If
Next iRow
MsgBox "Nicht ausgewählt wurden: " & vbLf & sDays
End Sub