Private Sub Worksheet_Change(ByVal target As Range)
If Intersect(target, [E11]) Is Nothing Then Exit Sub
Dim x$, i%, w As Worksheet
x = UCase(CStr([F11]))
ThisWorkbook.Unprotect "FifiSt" 'ôte la protection du classeur
For i = 5 To Worksheets.Count
Set w = Worksheets(i)
w.Visible = IIf(UCase(w.Cells(1)) = x, xlSheetVisible, xlSheetHidden) 'ou xlSheetVeryHidden
Next
ThisWorkbook.Protect "FifiSt" 'rétablit la protection du classeur
End Sub