function preventLink(event){
  if (event.preventDefault){
    event.preventDefault();
  }else{
    window.event.returnValue = false;
  }
}

function switchImg(link){
  imgLink = document.getElementById('imgContainer');
  imgLink.getElementsByTagName('img')[0].src = link.image;
  imgLink.href = link.link.replace('&','&');
  if (link.link.length == 0){
    if (!document.addEventListener && document.attachEvent){
      //impossible to implement on IE, it does not give reference information about clicked object
      imgLink.attachEvent('onclick', preventLink);
    }else{
      imgLink.addEventListener('click', preventLink, false);
    }
  }else{
    if (!document.addEventListener && document.attachEvent){
      imgLink.detachEvent('onclick', preventLink);
    }else{
      imgLink.removeEventListener('click', preventLink, false);
    }
  }
  document.oldSelectedAddElement.className = '';
  link.className = 'selected';
  document.oldSelectedAddElement = link;
}

function switchImage(event){
  if (event.preventDefault){
    event.preventDefault();
  }else{
    window.event.returnValue = false;
  }
  switchImg(this);
  clearInterval(document.addInterval);
}

function switchImageIE(){
  window.event.returnValue = false;
}

function showNext(){
  document.oldSelectedAddElementId++;
  if (document.oldSelectedAddElementId>4){
    document.oldSelectedAddElementId = 0;
  }
  switchImg(document.getElementById('customAdd').getElementsByTagName('li')[document.oldSelectedAddElementId].getElementsByTagName('a')[0]);
}

function configureAdd(imgList, linkList){
  liElements = document.getElementById('customAdd').getElementsByTagName('li');
  for (i = 0; i < liElements.length; i++){
    anhor = liElements[i].getElementsByTagName('a')[0];


    eventName = 'click';
    func = 'switchImage';
    capture = false;

    if (!document.addEventListener && document.attachEvent){
      //impossible to implement on IE, it does not give reference information about clicked object
      anhor.attachEvent('onclick', switchImageIE);
    }else{
      anhor.addEventListener('click', switchImage, false);
    }


    anhor.image = imgList[i];
    anhor.link = linkList[i];
    if (i==0){
      document.oldSelectedAddElement = anhor;
    }
  }
  document.oldSelectedAddElementId = 0;

  //switch to first element on start
  switchImg(document.getElementById('customAdd').getElementsByTagName('li')[0].getElementsByTagName('a')[0]);


  document.addInterval = setInterval('showNext()', 5000);
}