title: put c# datatable to extjs grid
body: <p>I use Extjs 3.4. In server side I have method which returns datatable with random structure (different columns, rows).</p>
  
  <p>I want to prepare one javascript file with extjs grid, which could take any datatable and show it in this grid. </p>
  
  <p>(When I know datatable structure, I create jsonReader to datagrid and I send json with date from datatable. But here, I have no idea how resolve it)</p>
  
  <p>Is it possible to do it? If yes, how?</p>