Two Macro's on one sheet

Hi,
I have the following which works a treat in range "h:h", but I want it to do the same thing for m:m and p:p
Any ideas?

Private Sub Worksheet_Change(ByVal Target As Range)
'Update 20140722
Dim WorkRng As Range
Dim Rng As Range
Dim xOffsetColumn As Integer
Set WorkRng = Intersect(Application.ActiveSheet.Range("h:h"), Target)
xOffsetColumn = 1
If Not WorkRng Is Nothing Then
    Application.EnableEvents = False
    For Each Rng In WorkRng
        If Not VBA.IsEmpty(Rng.Value) Then
            Rng.Offset(0, xOffsetColumn).Value = Now
            Rng.Offset(0, xOffsetColumn).NumberFormat = "dd/mm/yy"
        Else
            Rng.Offset(0, xOffsetColumn).ClearContents
        End If
    Next
    Application.EnableEvents = True
End If
End Sub