function set_rating(id, rating) {
  var a = $('rating_'+id).hasClassName('star') ? 16 : 20;
  $$('#rating_'+id+' .current')[0].setStyle('width: '+(rating*a)+'%;')
  if($('rating_'+id+'_na')) {
    if(rating == 0) {
      $('rating_'+id+'_na').addClassName('on');
    } else {
      $('rating_'+id+'_na').removeClassName('on');      
    }
  }
  $$('#rating_'+id+' input').each(function(e){e.checked = false});
  $('review_'+id+'_'+rating).checked = true;
}