Private Sub val_modif_Click()
Application.ScreenUpdating = False
Dim cel As Range, plage As Range, Reunion As String
Reunion = neutralise_creneau
Set plage = Sheets("creneaux").Range("a1:a" & Sheets("creneaux").Range("A" & Rows.Count).End(xlUp).Row)
For Each cel In plage
If cel.Value = Reunion Then
cel.Offset(0, 3).Value = places.Value
End If
Next cel
MsgBox ("modification effectuée")
neutralise_creneau.Value = ""
places.Value = ""
neutraliser.hide
End Sub