void xuatCBIndex(CBlist l, int index) {
	int k = 0;
	NodeCB *p = l.head;
	while (p->next != NULL && k != index) {
		++k;
		p = p->next;
	}
	cout << "ho ten phi cong :" << p->x.HoTenPhiCong << endl;
	cout << "MSCB: " << p->x.MS << endl;
	cout << "ngay bay: " << p->x.ngayBay.day << "/" << p->x.ngayBay.month << "/" << p->x.ngayBay.year << endl;
	cout << "Suc chua: " << p->x.succhua << endl;
}