How to handle user click the “delete button ” in setEditing in TableView?

I added a editButton on the table like this:

    self.navigationItem.leftBarButtonItem = self.editButtonItem;

and, having a setEditing method:

- (void) setEditing:(BOOL)editing animated:(BOOL)animated {
    [super setEditing:editing animated:animated];
    [self.watchListDetailTableView setEditing:editing animated:animated];
    if (editing) {
            // you might disable other widgets here... (optional)
    } else {
            // re-enable disabled widgets (optional)
    }
}

after I click the edit, I can have a cross and delete button, which method should I do to handle the delete button click? thank you.