title: Summary + ajax paging on ExtJS.Grid
body: <p>I have a grid with data similar to <a href="http://dev.sencha.com/deploy/ext-4.0.1/examples/grid/array-grid.html" rel="nofollow">http://dev.sencha.com/deploy/ext-4.0.1/examples/grid/array-grid.html</a>, but using paged proxy similar to <a href="http://dev.sencha.com/deploy/ext-4.0.1/examples/grid/paging.html" rel="nofollow">http://dev.sencha.com/deploy/ext-4.0.1/examples/grid/paging.html</a>.</p>
  
  <p>I need to add a summary similar to <a href="http://dev.sencha.com/deploy/ext-4.0.1/examples/grid/group-summary-grid.html" rel="nofollow">http://dev.sencha.com/deploy/ext-4.0.1/examples/grid/group-summary-grid.html</a>, only 1 at the bottom of the grid. It must sum all data, not only data from current page.</p>
  
  <p>I can make the DB query, no need Ext to sum the values. But how will I send the summary data to Ext.store and from store to grid?</p>