title: ItemFileWriteStore: how to change the data?
body: <p>I'd like to change the data in my dojo.data.ItemFileWriteStore.</p>
  
  <p>Currently I have...</p>
  
  <pre><code>var rawdataCacheItems = [{'cachereq':'14:52:03','name':'Test1','cacheID':'3','ver':'7'}];
  var cacheInfo = new dojo.data.ItemFileWriteStore({
          data: {
              identifier: 'cacheID',
              label: 'cacheID',
              items: rawdataCacheItems
          }
      });
  </code></pre>
  
  <p>I'd like to make a XHR request to get a new JSON string of the data to render.</p>
  
  <p>What I can't work out is how to change the data in the "items" held by ItemFileWriteStore.</p>
  
  <p>Can anyone point me in the correct direction?</p>
  
  <p>Thanks
  Jeff Porter</p>