If you want to UPDATE why are you using INSERT? Can you explain what you're trying to do?

>
>I try to update a file add value to the exiting value, the statement as follows:-
>
>INSERT INTO amaster
> (cmdb, cmcr, ccmdb, ccmcr)
>SELECT damt + amaster.cmdb AS Expr1, camt + amaster.cmcr AS Expr2, cdamt + ccmdb AS Expr3, ccamt + ccmcr AS Expr4
>FROM transact
>WHERE (acctno = amaster.acctno)
>
><snip>