window.onload = function(){
/*
*/
  var num = 1;
  setInterval(function(){
    document.getElementById('bannerLink' + num).style.display = 'none';
    num = document.getElementById('bannerLink' + (num+1))? ++num : 1;
    document.getElementById('bannerLink' + num).style.display = 'block';
  },6000);

}