gistfile1.js

var box = $('item9');
var tabs = box.select('h3');
var bodies = box.select('p');
var tab_color = '#ccc';
var selected = '#dd9';
tabs.invoke('setStyle','display:inline; padding:4px 8px; background-color:' + tab_color + '; margin:0; cursor:pointer');
bodies.each(function(elm){
  elm.hide();
  elm._tab = elm.previous('h3'); 
  box.insert({bottom:elm.remove()}); 
}).first().show();
tabs.first().setStyle({backgroundColor: selected}); //selected tab color
tabs.invoke('observe','click',function(evt){
  bodies.invoke('hide');
  tabs.invoke('setStyle',{backgroundColor: tab_color});
  var tab = this;
  tab.setStyle({backgroundColor: selected});
  var bods = bodies.findAll(function(elm){
    return elm._tab == tab;
  }); 
  bods.invoke('show');
});