// Making sure this code only executes when the document is loaded: this makes the DOM available to us  
 Event.observe(document, 'dom:loaded', function() {  
   
     // for every element with an toggler class...  
     $$('.pastToggle').each(function(element) {  
       
         // we put on an event listener of the click type  
         Event.observe(element, 'click', function(event){   
           
             // We stop the default link behaviour  
             Event.stop(event);  
           
             // when clicked, traverse the DOM: 1 step up (from it's A-element to it's container DIV-element),   
             // and select its following sibling (next(0)), and toggle that shit.  
             Event.element(event).nextSiblings().each(function(element){
                if(element.next('.past')) element.next('.past').toggle();
             });
         }, false);  
           
     });  
       
 });