Sub maprocedure
Dim CounterCheckBox As Integer, i As Integer
CounterCheckbox = 0
With LB_CheckBox
For i = 0 To .ListCount - 1
If .Selected(i) = True Then
CounterCheckbox = CounterCheckbox + 1
End If
Next
End With
If CounterCheckbox = 0 Then
MsgBox "Aucune case n'a été cochée."
Exit Sub
End If
End Sub