The property which was situated at Rouse Hill near Sydney was put up by the appellant, the mortgagee in possession, for sale by auction on 23 July 1977. The first respondent made a bid but the property was passed in. In the course of negotiations which then ensued in the agent's office between the first respondent, the agent's representative and Mr. Vaughan, the solicitor acting for the appellant, the first respondent made an offer of $76,000 which was accepted by Mr. Vaughan on the instructions of the appellant's wife. Mr. Vaughan had previously prepared in duplicate a form of contract, based on the Law Society-Real Estate Institute Form (1972 Copyright) and containing special conditions, and delivered it to the agent. The name of the purchaser, the purchase price, the amount of the deposit and the name of the purchaser's solicitor were not filled in. One copy bore the signature of the appellant, not witnessed. In the office, the other copy was handed to the first respondent who wrote in his name as purchaser as follows: "George Georgiou of 86 Wentworth Avenue, Sydney, or his nominee." The first respondent signed this copy and handed it back to the agent's representative with a cheque for $7,600 for the deposit. Mr. Vaughan then witnessed the appellant's signature on the first copy and handed it to the first respondent. At this time this copy did not state the name of the purchaser, the purchase price and the amount of the deposit on the first and last pages as well as the balance of the purchase money and the name of the purchaser's solicitor on the last page.