var cookie_path;
function toggle_category(id) {
  new Effect.toggle('category_' + id, 'blind', {duration: 0.2});
  var classes = new Element.ClassNames( 'category_name_' + id );
  var cname = 'toggle_category_' + id;
  var toggle = _COOKIE.get(cname);
  if ( toggle == 1 ) {
    classes.remove('on');
    classes.add('off');
    _COOKIE.unset(cname);
  } else {
    classes.remove('off');
    classes.add('on');
    _COOKIE.set(cname, 1, null, cookie_path);
  }
}

function init_category(id) {
  var category_name = 'category_name_' + id;
  if ( _COOKIE.get( 'toggle_category_' + id ) != 1 ) {
    $( 'category_' + id ).style.display = 'none';
    Element.removeClassName( category_name, 'on'  );
    Element.addClassName(    category_name, 'off' );
  }
  $( category_name ).innerHTML = '<a href="javascript:void(0)" onclick="toggle_category(' + id + ')">' + $( category_name ).innerHTML + '<' + '/a>';
}