>Thank for your reply Crescencio.
>I tryed this but when I go to the next record in the grid the preview record desappear the combo value and in other way When I shoudl do set filter to.???

The assumption I made was that you had three comboboxes, three different cursors as their rowsource (one each), and that you would set a filter to the second and third cursors once selections were made on the first and second comboboxes, respectively.

Do you have this comboboxes inside a Grid?

What are the rowsourcetype and rowsource properties for each combobox? If you post some sample code maybe it'll be clear.