Oh, yes, here trigger should not work because it does not support recursive action, meaning you can use trigger to update another table, but not the table trigger based on.

>Yuri,
>
>The trigger won't work. Each trigger that fires makes the record readonly and freezes the record pointer until the trigger exits.
>
>In fact, the RecordValidation is the only place Steven can use
>
>>See VFP HElp for :
>>CREATE TRIGGER ON TableName
>> FOR DELETE | INSERT | UPDATE AS lExpression
>>
>>For instance you may use custom routine/program for lExpression.
>>>Hi All,
>>>
>>>I'm stuck on this very basic (at least I think it is) VFP database design issue.
>>>
>>>I've got a table with three fields, LENGTH, WIDTH and AREA. I'd like to have the AREA field automagically update its value with the product of LENGTH and WIDTH whenever either of those two values change.
>>>
>>>This update must occur under the following circumstances:
>>>
>>>1) the table is browsed to make edits to the LENGTH and/or WIDTH columns.
>>>2) the table is appended to.
>>>3) the LENGTH and/or WIDTH is modified on a form containing controls bound to them.
>>>
>>>I believe that I need to do something in the database container to "trigger" this but where and how?
>>>
>>>TIA.
>>>
>>>Mike