How to Use Or in SQL Statement

I would like to know how to use Or in your SQL Statement. Please look at the below SQL Statement that I have:

              'Start SQL statement
              strSQL = "Select * From SpaStore, Area, State"
              strSQL = strSQL & " where SpaStore.Area = Area.AreaID"
              strSQL = strSQL & " and State.State = Area.State"

              strSQL = strSQL & " and ListingType='Featured' or 'National'"
    strSQL = strSQL & " and Approve=0"
    strSQL = strSQL & " Order By SpaStoreName"

I would like for records with both listingtype of Featured and National to show up. But this sql statement won't work. How do I get records for both listing types? Thanks!