function reload_page(){
  document.location='statistiche.php?id='+document.filter_date.id_stat.value+'&year='+document.filter_date.anno.value+'&month=0';
}

function reload_page2(){
  document.location='statistiche.php?id='+document.filter_date.id_stat.value+'&year='+document.filter_date.anno.value+'&month='+document.filter_date.mese.value;
}