Parameter Not Found Delphi

var
    campo:string;
begin
       campo:=column.fieldname;
       dm.qTarefaHisUsu.close;
       dm.qTarefaHisUsu.sql.text:='SELECT * FROM GTELHIS LEFT OUTER JOIN GTELTAREFA ON (GTELTAREFA.ID = GTELHIS.ID_TAREFA)'+
       'LEFT OUTER JOIN GTELEVE ON (GTELEVE.CODEVEEV = GTELHIS.CODEVEHI) LEFT OUTER JOIN GTELOPE ON (GTELOPE.CODOPEOP = GTELHIS.CODOPEHI) WHERE GTELHIS.ID_TAREFA=:WID'+
       'order by '+campo;
       DM.qTarefaHisUsu.Parameters.ParamByName('WID').VALUE := DSTARUSU.DATASET.FIELDBYNAME('ID').VALUE;
       if not dm.qTarefaHisUsu.Prepared then
              dm.qTarefaHisUsu.Open;
end;