class Item class
cancel to undo modifications made to one or more fields belonging to
the current record, as long as those changes are not already posted to the item
triggers the on_before_cancel event handler if one is defined for the item.
to undo modifications made to the current record and its details if the record has been edited or removes the new record if one was appended or inserted.
puts the item into browse state
triggers the on_after_cancel event handler if one is defined for the item.
updates data-aware controls