Private Sub CommandButton1_Click()
Dim cell As Range
If Range("M29") = "Prix TTC" Then
Range("M29") = "Prix HT"
Range("N29") = "TTC 19.6 %"
Range("O29") = "TTC 5.5 %"
For Each cell In Range("M30:M37")
cell.Offset(0, 1) = cell * 1.196
cell.Offset(0, 2) = cell * 1.055
Next
Else
Range("M29") = "Prix TTC"
Range("N29") = "HT 19.6 %"
Range("O29") = "HT 5.5 %"
For Each cell In Range("M30:M37")
cell.Offset(0, 1) = cell / 1.196
cell.Offset(0, 2) = cell / 1.055
Next
End If