sql*plus question

Hi,

[Quoted] [Quoted]         This has got to be an easy one but my brain has gone dead and I can't work it out.
[Quoted]  I would appreciate any clues to the answer.

I have two tables header and detail which have a master-detail relationship [Quoted] with invoice as the key.

header

	invoice  varchar2(10)
	ref         varchar2(5)
	other stuff. .

detail
	invoice varchar2(10)
              other stuff. . .

I want to amend the invoice number for both header and detail if the ref in [Quoted] the header holds a particular value

eg should become
Header:-

 	invoice 123456		invoice 97123456
	bref      CHANGE		bref      CHANGE	

Detail:-
	invoice 123456		invoice 97123456

I would like to do this in one pass if possible

Help!!!!
Yours gratefully

Sally Pearce
Financials DBA(for my sins) Received on Thu Jul 17 1997 - 00:00:00 CEST