>>>>>>>>>I have a Form with parent/child forms. Is multi users.
>>>>>>>>>when I insert a record and many users use the form, the error is produced. and I then select an option (cancel or ignore) and the application break!
>>>>>>>>>
>>>>>>>>>I use bufferMode = 3
>>>>>>>>>And begin - end transacction when insert record
>>>>>>>>
>>>>>>>>What is the error message? Presumably, inserting new record can produce nothing more then index uniqueness violation.
>>>>>>>
>>>>>>>The problem is when they are many users using the System. And the worst it is that the system breaks after showing the message of error.
>>>>>>
>>>>>>I got it already; but what is the error message?
>>>>>
>>>>>when there are many users inserting in the same table, the error occurs.
>>>>
>>>>What error? If you want to get any kind of technical assistance here, then you should post literal error message, at least.
>>>
>>>Record is in use by another user (Error 109)
>>
>>What do you use to insert a record: APPEND or INSERT-SQL? The latter way shouldn't create any access problems.
>
>I use INSERT - SQL

So, the reason is in another place. What's the idea to use transaction here? Do you update some other tables too?