In my opinion this appeal should be dismissed and my reasons are these On the findings of the High Court it appears that the Bank had agreed to allow an overdraft to defendant No. 1 for Rs. 20,000/ , that the appellant gave a surety bond for the repayment of Rs. 25,000/ and when that was pointed out to defendant No. 1, the principal debtor, lie (the latter) made the alteration in the document by reducing the figure of Rs. 25,000/ to Rs. 20,000/ The case of the appellant was not that he never stood surety for defendant No. 1 but that he stood surety for Rs. 25,000/ which was subsequently altered to Rs. 20,000/ and that any change of figure was a material alteration resulting in the avoidance of the contract, even though the alteration might have been advantageous to him, the obliger.