Q about SELECT ... FOR UPDATE

I am preparing a locking cursor like this: select * from table where serial_column = ? and stat_column not in (..)for update The idea here is to consider the row with stat_column set to certain values already locked and to prevent an actual lock from being placed. When the fetch reads such a row, status = notfound (as expected) but the row whose serial_column is set to ? becomes locked. My environment includes 4GL 4.11 and OnLine 7.1 with transactions and dirty read. Thanks for any info. Edwin Babadaglian edwinb@panix.com