@Override
	public void checkOut(String borrower, String date) {		
	if(state == 0){
		this.borrower = borrower;
		this.checkOutDate = date;
		this.state = 1;  // ϸ ¸ 1 ٲ.
		System.out.println("*"+bookTitle+"() Ǿϴ.");
		System.out.println(":"+this.borrower);
		System.out.println(":"+this.checkOutDate);
	}else{
		System.out.println(" Ұ մϴ.");
		}
	}