Here is my problem: I have 2 tables Accounts and Transaction Logs. in Accounts table, it has column "Amount" which is a base amount of an account. and in Trans Logs table, it also has column "Amount" which is additional (add or minus to the base amount) amount of the account. and I don't know how to retrieve that base amount to edit it, then save it back to the table. That means I need to get a value of the right column by using Acc_No to find. I'm using DataSet, by the way. i think it should go like this: Dim Amount as Decimal Amount = *the code to retrieve the base amount* Amount = Amount + txtAmount.Text *the code to save the new amount back to Accounts table* Thank you!