Event.observe(window, 'load', function() {
  bannerRotation();
});

function bannerRotation(){
  if($('dietzk-slideimage')){
    new PeriodicalExecuter(changeBannerRotation, 5);
  }  
}

function changeBannerRotation(){
  if($('dietzk-slideimage')){
    var allBanner = $('dietzk-slideimage').select('.banner-rotation').length;
    if(allBanner > 0){
      var currentIndex = 0;
      for (var i=0, il = allBanner; i < il; i++) {
        if($('dietzk-slideimage').select('.banner-rotation')[i].style.display =="block") {
           $('dietzk-slideimage').select('.banner-rotation')[i].hide();
           currentIndex = i;
        }
      }  
      if(currentIndex == (allBanner-1)){
         currentIndex = 0;
      }else{
         currentIndex++;
      }
      $('dietzk-slideimage').select('.banner-rotation')[currentIndex].style.display= "block";
    }
  }
}