hi there. the general rule concerning revocation is that the offer must be rescinded and the revocation must reach the offeree before the offer is accepted. Furthermore, since the cheque was placed in the mail by your client before the revoction of the offer appeared in the newspaper, on the strength of the 'postal rule,' your client accepted the offer. Once an offer is accepted it cannot, legally, be rescinded. Your client will prevail on the basis that the offer was not revoked before acceptance (as acceptance took place when the letter and cheque were mailed.) (i hope you client has proof that (s)he mailed the letter on that day, however.) Hope this helps, although i am assuming i am about 2 months too late.