public int delete(Book deletebook) throws ClassNotFoundException{

		collectionb.removeElement(deletebook);
		int booknum = this.getBookCount();
		booknum--;
		this.setBookCount(booknum);

		try{
			ObjectOutputStream oob = new ObjectOutputStream(new FileOutputStream("bookcollection.txt"));
			oob.writeInt(this.getBookCount());
			for(int i = 0; i<this.getBookCount() ; i++){
				oob.writeObject(collectionb.elementAt(i));
			}
			oob.close();
		}catch(IOException e){
		}
		System.out.println("  Ϸ!");

		return 1;
	}