defendant was liable to pay an amount of Rs.6,954/- as balance amount due under prior transaction. To substantiate the oral evidence there is no evidence other than the uncontroverted testimony of the plaintiff himself. It is the case of the appellant that there was an oral agreement for the same. No evidence either oral or documentary had been produced to substantiate at least the contention that there was a prior transaction between the plaintiff and the defendant. Even if no other evidence to prove the oral evidence, certainly he could have produced some evidence to show the prior transaction under which he is claiming Rs.6,954/-. Secondly, as rightly noted by the appellate court, it is improbable to believe that the defendant orally agreed to pay Rs.6,954/- on 11.5.1995 on which day he executed Ext.A1 pro-note in his favour acknowledging the debt coming to the tune of Rs.21,000/-. Had he agreed to pay Rs.6,954/- also, certainly that amount would have been included in the promissory note, particularly when both agreements were on the same day. In the above view the plaintiff miserably failed to prove the oral agreement under which the defendant