private String makeCookie(String id, HttpServletRequest request) {
		Cookie cookies[] = request.getCookies();
		String bookHistroy = null;
	//	System.out.println("length:  "+cookies.length);
		for(int i = 0; cookies != null && i < cookies.length; i++){
			System.out.println("length_for:  "+cookies.length);
			if(cookies[i].getName().equals("bookHistroy")){
				System.out.println();
				bookHistroy = cookies[i].getValue();
			}
		}
		if(bookHistroy == null){
			bookHistroy = id;
			return bookHistroy;
		}
		String ids[] = bookHistroy.split("_");
		LinkedList<String> idList = new LinkedList(Arrays.asList(ids));
		System.out.println(idList);
		if(idList.contains(id)){
			idList.remove(id);
		}else{
			if(idList.size() == 3){
				idList.removeLast();
			}
		}
		idList.addFirst(id);
		
		StringBuffer sb = new StringBuffer();
		for(String lid : idList){
			sb.append(lid + "_");			
		}
		
		
		return sb.deleteCharAt(sb.length()-1).toString();
	}