Macro défusionner URGENNT !!!!!!!!!!

Dim c As Range, plage As Range
If [B3].MergeCells Then
    Set plage = [B3].MergeArea
    [B3].UnMerge
    For Each c In plage
        c.Value = [B3]
    Next c
End If

Sub défusionne()
    Dim c1 As Range, c2 As Range, plage1 As Range, plage2 As Range
    Application.ScreenUpdating = False
    Set plage1 = Selection
    For Each c1 In plage1
        If c1.MergeCells Then
            Set plage2 = c1.MergeArea
            c1.UnMerge
            For Each c2 In plage2
                c2.Value = c1
            Next c2
        End If
    Next c1
    Application.ScreenUpdating = True
End Sub