function setActive(totalFrames,action,target){

  currentFrame = document.getElementById("current_slide").value;
  
  if(action == 'previous'){
  
    if(currentFrame == 1){
    
      currentFrame = totalFrames;
    
    }else{
    
      currentFrame = currentFrame - 1;
    
    }    
  
  }else if(action == 'next'){    
  
    if(currentFrame == totalFrames){
    
      currentFrame = 1;
    
    }else{
      
      currentFrame = parseInt(currentFrame) + 1;
    
    }
    
  
  }else{
  
      currentFrame = target;
  
  }
  
  for(var i = 1;i <= totalFrames;i++){
  
    document.getElementById("sample_photo_"+i).style.display = "none";
        
  }

  document.getElementById("sample_photo_"+currentFrame).style.display = "block";

  document.getElementById("current_slide").value = currentFrame; 

  clearTimeout(looper);
  looper = setTimeout("startTimer(totalFrames)",5000);
  
}

function startTimer(totalFrames){
  
  setActive(totalFrames,'next',0);
  
}