For P = Cells.SpecialCells(xlCellTypeLastCell).Row To 2 Step -1
If IsEmpty(Cells(P, 10).Value) Then
Select Case Cells(P, "i").Value
Case "tata": Cells(P, 10).Value = "A"
Case "toto": Cells(P, 10).Value = "B"
Case "titi": Cells(P, 10).Value = "C"
Case "juju": Cells(P, 10).Value = "D"
Case "jojo": Cells(P, 10).Value = "E"
Case "gigi": Cells(P, 10).Value = "F"
End Select
End If
Next P