Company has two partners A and B.....the finished goods are selled to customer and out bill was signed by Person A...and the payment is received by..A in cash....due to some problems factory is closed...after two months B enquired to customer about the pending of cash payment....he says it already given to A....and the person B lodged complaint in station.....they asked to submit cash received receipt.......in that station the person A fakes the sign of B in receipt and submitted and said Person B has got the cash amount from customer....now how to prove that sign is fake? And court can deal this?