fn fnmatidassign matidvalue=
    (
        try
        (
            obj =selection[1]

            num_faces = 0
            if classof obj == polymeshobject then
            (
                polyop.getfaceselection obj
                num_faces = polyop.getNumFaces obj

            )
            else
            (
                getfaceselection obj
                num_faces = getNumFaces obj
            )


            if num_faces > 0 then
                for f = 1 to num_faces do
                    setFaceMatID obj f matidvalue

            update obj
        )

        catch
        (
            messagebox "Please select an object that  :\n- Is a collapsed mesh\n- With a  Multi/Sub-Object Material applied "
        )
    )


    fnmatidassign 20    -- TEST