class error_titlu(Exception):
    pass

class error_descriere(Exception):
    pass


class error_autor(Exception):
    pass


class error_nume(Exception):
    pass


class error_cnp(Exception):
    pass


class error_find(Exception):
    pass


class error_save(Exception):
    pass


class error_delete(Exception):
    pass


class error_update(Exception):
    pass


class error_imprumut1(Exception):
    pass


class error_imprumut2(Exception):
    pass