[AccessD] Changing Criteria

Hi Folks

Is it possible to do the following:

I have a query where one of the fields references a text box containing a Filter Code to pick up the required selection criteria for the query. It works fine for Case 1 to 6 but what is the syntax to make Case 7 and 8 work?

Private Sub HotelFilter_AfterUpdate()
    Select Case HotelFilter
        Case Is = 1
            FilterCode = "FH"
        Case Is = 2
            FilterCode = "FHI"
        Case Is = 3
            FilterCode = "LH"
        Case Is = 4
            FilterCode = "B"
        Case Is = 5
            FilterCode = "L"
        Case Is = 6
            FilterCode = "E"
        Case Is = 7
            FilterCode =      Display only those records that do not have a code ie Code is Null
        Case Is = 8
            FilterCode =      Display all records ie no filter
       End Select
    Me.Refresh