thx for your help guys

yah each product has a unique serial!..., for that it depend on quantity

if quantity of a product is 25 piece = we will need 25 serial number

tblSerial (SerialId, ProdId, Quantity, SerialNumber)
here , we have to make the quantity 1 for each product!!!!

because qty and serial in the same table....

i think we need another table for serials..