title: iPhone:Add & Delete Row in UITableview with editing mode
body: <p>What I want to do is:</p>
  
  <ol>
  <li><p>Setting editing mode on NavigationBar in UITableView adds an <code>edit</code> button on the left side of the UINavigationBar.  When I click this button, I'd like an <code>add</code> button to appear on the right side of the NavigationBar.</p></li>
  <li><p>When I click on the <code>add</code> button, add a row to the NSMutableArray and update the table.</p></li>
  </ol>
  
  <p>So please give me ideas, code, or links to develop this functionality.</p>