var lastDiv='';
function switchDiv(to,scrollto) {
  var toFx = new Fx.Style(to,'opacity');
  toFx.set(0);
  var oldLastDiv = lastDiv;
  if ((lastDiv != '') && (lastDiv != to)) {
    var transFx = new Fx.Style(lastDiv,'opacity');
	transFx.start(1,0).chain(
	   function() {
         $(to).setStyle('display','block');
	     $(oldLastDiv).setStyle('display','none');
         toFx.start(0,1);
	   }
	);
  } else {
    $(to).setStyle('display','block');
    toFx.start(0,1);
	// new Fx.Scroll(window).toElement($(scrollto));
  }
  lastDiv = to;
}