I got the message
"Record has been updated by another user.Re-query to see the changes"
whenever i try to modify the master record on my form or some times for detail record.
if any one knows the solution please let me know
thanx a lot.
It could mean what it says, i.e. that another user has updated the record since you queried it (that "other user" could be you, e.g. in a separate SQL Plus session).
More likely though, if it happens often, is that you are using an UPDATE statement in your form that updates the record you are viewing. You should avoid doing this, letting the form handle the updates theough its own mechanism.
Database triggers? That would do it for sure. Once the database triggers fire and update the record, any columns that were updated by the trigger but are also queried by the form will be out of sync. You need to requery the record to see it as it is now. Or you can avoid the issue by not including those columns in the form (if that is possible).