at the address of the offeror on the last day of the period because that day falls on an official holiday or a non-business day at the place of business of the offeror,the period is extended until the first business day which follows. Article 21 (1)A late acceptance is nevertheless effective as an acceptance if without delay the offeror orally so informs the offeree or dispatches a notice to that effect. (2)If a letter or other writing containing a late acceptance shows that it has been sent in such circumstances that if its transmission had been normal it would have reached the offeror in due time,the late acceptance is effective as an acceptance unless,without delay,the offeror orally informs the offeree that he considers his offer as having lapsed or dispatches a notice to that effect. Article 22 An acceptance may be withdrawn if the withdrawal reaches the offeror before or at the same time as the acceptance would have become effective. Article 23 A contract is concluded at the moment when an acceptance of an offer becomes effective in accordance with the provisions of this Convention. Article 24 For the purposes of this Part of the Convention,an offer,declaration of acceptance or any other indication of intention "reaches"the addressee when it is made orally to him or delivered by any other means to him personally,to his place of business or mailing. (General Provisions) Article 25 A breach of contract committed by one of the parties is fundamental if it results in such detriment to the other party as substantially to deprive him of what he is entitled to expect under the contract,unless the party in breach did not foresee and a reasonable person of the same kind in the same circumstances would not have foreseen such a result Article 26 A declaration of avoidance of the contract is effective only if made by notice to the other -5-- 5 - at the address of the offeror on the last day of the period because that day falls on an official holiday or a non-business day at the place of business of the offeror, the period is extended until the first business day which follows. Article 21 (1) A late acceptance is nevertheless effective as an acceptance if without delay the offeror orally so informs the offeree or dispatches a notice to that effect. (2) If a letter or other writing containing a late acceptance shows that it has been sent in such circumstances that if its transmission had been normal it would have reached the offeror in due time, the late acceptance is effective as an acceptance unless, without delay, the offeror orally informs the offeree that he considers his offer as having lapsed or dispatches a notice to that effect. Article 22 An acceptance may be withdrawn if the withdrawal reaches the offeror before or at the same time as the acceptance would have become effective. Article 23 A contract is concluded at the moment when an acceptance of an offer becomes effective in accordance with the provisions of this Convention. Article 24 For the purposes of this Part of the Convention, an offer, declaration of acceptance or any other indication of intention "reaches" the addressee when it is made orally to him or delivered by any other means to him personally, to his place of business or mailing. (General Provisions) Article 25 A breach of contract committed by one of the parties is fundamental if it results in such detriment to the other party as substantially to deprive him of what he is entitled to expect under the contract, unless the party in breach did not foresee and a reasonable person of the same kind in the same circumstances would not have foreseen such a result. Article 26 A declaration of avoidance of the contract is effective only if made by notice to the other