6 The claim of the plaintiffs was that there was an oral agreement made between Mr Klobas acting on behalf of MJK and Mr Mario Minuzzo representing the defendant to the effect that the defendant would pay to MJK commission in the sum of $300,000 if a company called Harvey Norman Holdings Limited ("Harvey Norman") were to enter into a commitment with the defendant to take a lease of a property in the southern suburbs of Adelaide, with a site area of some 10,000 square metres and suitable for the erection of a retail showroom and warehouse for use by Harvey Norman in connection with its business. The plaintiffs allege that the agreement was constituted by a conversation in June of 1996 between Mr Klobas and Mr Mario Minuzzo, the effect of which was that if the commitment described was established, then a fee of $300,000 would be paid by the defendant to MJK. While the defendant admitted that an unwritten agreement had been made, it denied that the agreement concerned was made in terms alleged by the plaintiffs. The defendant contended that before the $300,000 was payable, a site had to be located and purchased, Harvey Norman had to enter into a commitment to lease the property, a showroom and warehouse had to be erected and the completed development sold to an investor and the sale completed. This appeal is concerned with a judgment of the District Court for the payment of the above fee of $300,000 less an amount of $25,000, which amount will be further explained later in these reasons.