title: remove a tab item in extjs
body: <p>I have a code as follows</p>
  
  <pre><code>var tabs1 = new Ext.TabPanel('tabs2');
  idHistoryReportsTabItem = tabs1.addTab('script1', idHistoryReportsTabCaption);
  seatHistoryReportsTabItem = tabs1.addTab('markup1', seatHistoryReportsTabCaption);
  tabs1.activate("script1");
  </code></pre>
  
  <p>i want to remove tab item markup1 from the tabs2, how do i do?</p>