VBA to hide and unhide columns based on 2 criteria

Hi everyone,

I'm relatively new to VBA's so need a bit of help please...

I'm looking to hide columns L through to Q when cell 'S1' returns 0 and unhide them all again when it goes blank. I've managed to use the below code to get this to work -
Private Sub Worksheet_SelectionChange(ByVal Target As Range)

   If Range("S1").Value = 0 Then
        Columns("L").EntireColumn.Hidden = True
        Columns("M").EntireColumn.Hidden = True
        Columns("N").EntireColumn.Hidden = True
        Columns("O").EntireColumn.Hidden = True
        Columns("P").EntireColumn.Hidden = True
        Columns("Q").EntireColumn.Hidden = True
    Else
        Columns("L").EntireColumn.Hidden = False
        Columns("M").EntireColumn.Hidden = False
        Columns("N").EntireColumn.Hidden = False
        Columns("O").EntireColumn.Hidden = False
        Columns("P").EntireColumn.Hidden = False
        Columns("Q").EntireColumn.Hidden = False
    End If
End Sub

However I need another criteria in there too. If cell 'T1' returns 0 I would like to hide column P only and unhide when the cell goes blank. Both cells won't return 0 at the same time. I've tried adding another IF but seems to fail.

Any help would be appreciated!