var Collapsibles = {
  els : Array,
  init : function() {
    Collapsibles.els = document.getElementsByClassName('sekcja-rozwijana');
    Collapsibles.attach();
  },
  attach : function() {
    var i;
    for ( i=0;i<Collapsibles.els.length;i++ ) {
      var activator = Collapsibles.els[i].getElementsByClassName('unwrapper')[0];
      Event.observe(activator,'click',Collapsibles.collapse,false);
      Element.cleanWhitespace(Collapsibles.els[i].parentNode);
    }
  },
  getEventSrc : function (e) {
    if (!e) e = window.event;
    if (e.originalTarget)
      return e.originalTarget;
    else if (e.srcElement)
    return e.srcElement;
  },
  collapse : function(e) {
    var activator = Collapsibles.getEventSrc(e);
    var el = Collapsibles.getEventSrc(e).previousSibling;
    if ( Element.hasClassName(el,'opened') ) {
      new Effect.Parallel(
        [
          new Effect.SlideUp(el,{sync:true}),
          new Effect.Fade(el,{sync:true})
        ],
        {
          duration:1.0,
          fps:40
        }
      );
      activator.innerHTML = 'Czytaj więcej...';
      Element.removeClassName(el,'opened');
    } else {
      new Effect.Parallel(
        [
          new Effect.SlideDown(el,{sync:true}),
          new Effect.Appear(el,{sync:true})
        ],
        {
          duration:1.0,
          fps:40
        }
      );
      activator.innerHTML = 'Zwiń';
      Element.addClassName(el,'opened')
    }
  }
};
Event.observe(window,'load',Collapsibles.init,false);