//------------------------------------------------------------------
function change_page(hash) {

  if (hash) {
    if (location.hash && $(location.hash.substr(1))) {
      Effect.DropOut(location.hash.substr(1));
    } else if (location.hash == '') {
      Effect.DropOut('top');
    }
    if (!$(hash)) {
      hash = 'top';
    }
    location.hash = '#' + hash;
    setTimeout(function(){new Effect.Appear(hash)}, 500);
  } else {
    if (!location.hash || !$(location.hash.substr(1))) {
      hash = 'top';
    } else {
      hash = location.hash.substr(1);
    }
    $(hash).show();
  }
}

$('top').style.display = 'none';

Event.observe(window, 'load', function(){return change_page();});