Filed Filter and Serial Nos.

Hi,

If I have a Serial Nos. on a primary key on a form with manual option for this series.
I have problems if the users press F7 to search for a specific no.
If the number is not found the system try to create a new one and from this moment the system creates blank records every times a search value is not found.
I do not know a solution for this kind of problem, maybe to deactivate Field Filter on form or else.

Thanks.