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[Silvia Berti]

I use mapserver 3.4 and i try to use  a logical expressions of class obiect.
This is my map file's fragment:

 layer
    classitem "Code"
    data "d:/data/maps/mapdata/shape/hydro34_polyline_clip.shp"
    header "rivers_header.html"
    maxscale 1000000
    minscale 150000
    name "Rivers"
    status on
    type line
    # 1 query #none
    query
      template "rivers_query.html"
    end
    # 2 class Rivers
    class
      color 0 255 255
      expression "([Code] > 1)"
      name "Rivers"
    end
  end

I don't receive any error message but i don't display anything in the map.
Excuse me for my english.
                                     Thank you