Private Sub lstDays_DblClick(ByVal Cancel As MSForms.ReturnBoolean)
Dim iIdx As Integer
Dim sNew As String
sNew = InputBox("Neuen Eintrag eingeben:")
If sNew = "" Then Exit Sub
With lstDays
iIdx = .ListIndex
.RemoveItem .ListIndex
.AddItem sNew, iIdx
End With
End Sub