But I think you would be better using a local/global variable of the same table. My guess is you are doing SETSELECTIONFILTER(rec) and you should be doing SETSELECTIONFILTER(variable)
Thanks for the quick reply. Actually I am just a beginner in Nav, but your reply just solved my problem.
Actually what I intend to do is use the CurrForm.SETSELECTIONFILTER(Rec) to identify the record selected by user in a form, then copy these record to another table.
Finally I use the MARKEDONLY := FALSE, so that the form will continue to show all the other records which are not selected by a user.
By the way, I use this for the purpose of customization.