macro enregistrer sous PDF changement de nom du document

Option Explicit

Sub SaveAsPDF()
Dim sNom As String
    sNom = Worksheets("mise en page").Range("L19")
    If NomFichierValide(sNom) Then
        ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
                "C:\Users\Christophe\Desktop\" & sNom, Quality:= _
                xlQualityStandard, IncludeDocProperties:=True, IgnorePrintAreas:=False, _
                OpenAfterPublish:=False
    Else
        Worksheets("mise en page").Range("L19").Select
    End If
End Sub

Private Function NomFichierValide(sChaine As String) As Boolean
Dim i As Long
Const CaracInterdits As String = """*/:<>?[\]|"
    NomFichierValide = True
    If Len(sChaine) = 0 Then
        NomFichierValide = False
        Exit Function
    End If
    For i = 1 To Len(CaracInterdits)
        If InStr(sChaine, Mid$(CaracInterdits, i, 1)) > 0 Then
            NomFichierValide = False
            Exit Function
        End If
    Next i
End Function