>I found the code combination
>

>APPEND BLANK IN vitems
>REPLACE ...
>

>
>I want to enclose the transaction in Begin Transacation, End Transaction/Rollback constructs so I can back out transactions if the Tableupdate fails.
>
>Can use the above construct or should I change to the Insert into construct?

INSERT INTO should be faster. If that is no concern, you can use both alternatives - APPEND FROM / REPLACE is sometimes easier to manage.

>This is called in from other forms and currently the buffermode is 0. Do I need to change it to 2?

Without buffering, the combination can fail, because of some sort of violation: missing value in field, RI, etc.

Let's see what happens:

* No buffering:
APPEND BLANK && immediately fails! Missing FK, for instance.
REPLACE...

* With buffering:
APPEND BLANK && Triggers are not yet evaluated
REPLACE... && Here, you insert the necessary values
TableUpdate() && Only now are certain rules evaluated.

>Anything else I should do?

Optimistic buffering is the preferred method, for most developers. (Options 3 or 5.)