PHP mapscipt: clone()

[Gianfranco Brescia]

Hi to all!
how do I have to use clone()?
Is my script correct?

....
$selezionati = $this->selezionati;
$layer = $this->map->getLayerByName('polli');
$classeselezionati = $layer->getclass(1);
foreach ($selezionati as $v)
       {
        $classi[$i] = ms_newClassObj($layer);
        $classi[$i] = $classeselezionati->clone();
        $classi[$i] -> setexpression($v);
        $i = $i+1;
       }
...

Mapfile:

....
CLASSITEM "codice_all"
     CLASS
          NAME       "centrobuffer"
          STYLE
               SYMBOL   bollo
               SIZE     5
               COLOR    255 0 0
          END
          EXPRESSION  '0'
     END
     CLASS
          NAME       "selezionati"
          STYLE
               SYMBOL   bollo
               SIZE     4
               COLOR    0 255 0
          END
          EXPRESSION  '0'
     END
     CLASS
          NAME       "noselezionati"
          STYLE
               SYMBOL   bollo
               SIZE     3
               COLOR    150 150 250
          END
          EXPRESSION /./
     END
.....


Thank you! Ciao.