>>>>>>>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.