var activeMultiPage;
function initPages(active) {
  var activepage = YAHOO.util.Dom.get('page' + active);
  if (activepage) {
	activeMultiPage = active;
	var allpages = YAHOO.util.Dom.getElementsByClassName('multiPage', 'div');

    YAHOO.util.Dom.setStyle(allpages, 'display', 'none');
    YAHOO.util.Dom.setStyle(activepage, 'display', 'block');
    YAHOO.util.Dom.setStyle(activepage.firstChild.firstChild, 'opacity', '0');

    var ani = new YAHOO.util.Anim(activepage.firstChild.firstChild, { opacity: { to: 1 } }, 1);
    ani.animate();
    if (YAHOO.util.Dom.get('page' + (active+1))) {
  	  //YAHOO.util.Dom.get('fadeRight').innerHTML = YAHOO.util.Dom.get('page' + (active+1)).firstChild.firstChild.innerHTML;
  	  YAHOO.util.Dom.setStyle('multiPageNext', 'opacity', '1');
    }
    else {
  	  //YAHOO.util.Dom.get('fadeRight').innerHTML = '';
  	  YAHOO.util.Dom.setStyle('multiPageNext', 'opacity', '0.2');
    }
    if (YAHOO.util.Dom.get('page' + (active-1))) {
      //YAHOO.util.Dom.get('fadeLeft').innerHTML = YAHOO.util.Dom.get('page' + (active-1)).firstChild.firstChild.innerHTML;
      YAHOO.util.Dom.setStyle('multiPagePrev', 'opacity', '1');
    }
    else {
  	  //YAHOO.util.Dom.get('fadeLeft').innerHTML = '';
  	  YAHOO.util.Dom.setStyle('multiPagePrev', 'opacity', '0.2');
    }
  }
}

function nextPage() {
  initPages(activeMultiPage+1);
}
function prevPage() {
  initPages(activeMultiPage-1);
}
function changePage(delta) {
  if (delta < 0) {
    nextPage();
  } else if (delta > 0) {
    prevPage();
  }
}

function mouseWheel(e, fn) {
  YAHOO.util.Event.stopEvent(e);
  if (e.wheelDelta) {
    var d = e.wheelDelta/120;
    if (window.opera) { d = -d; }
  } else if (e.detail) { var d = -e.detail/3; }
  if (d && fn) { fn(d); }
}

YAHOO.util.Event.on(window, 'load', function(e){
  initPages(1);
  YAHOO.util.Event.on('multiPageContainer', 'DOMMouseScroll', mouseWheel, changePage);
  YAHOO.util.Event.on('multiPageContainer', 'mousewheel', mouseWheel, changePage);
});