locking sub-form only

[Cagdas Ozgenc]

Greetings.

I have a form with a subform. Main form is attached to table of
branches of our company, and sub form is attached to an orders table.
Two tables are linked through branch id.

When a user edits an order line the entire branch record is locked,
and no other user can edit orders. However I just want to lock that
specific order line, without blocking access to the entire branch.

For this to happen which lock setting must be applied to each form?
Currently I applied recordwise locking to subforms only but it doesn't
work.

Thanks