Adding New Discussion and replying to the Discussion Item using Object Model

New Discussion:

SPListItem oListItem =SPUtility.CreateNewDiscussion(oList.Items, TitleField.Text);

oListItem[SPBuiltInFieldId.Body] = MessageBox.Text;

         oListItem.Update();
 Discussion reply:

SPListItem parent = list.GetItemById(parentId);

         SPListItem reply = SPUtility.CreateNewDiscussionReply(parent);

reply[SPBuiltInFieldId.Body] = body;

                  reply.Update();