title: How to edit cell in grid panel in Ext JS 3.4?
body: <p>Is it possible to make cell editable in ext js 3.4 <code>gridpanel</code>?</p>
  
  <p>If yes please reply me how?</p>
  
  <blockquote>
    <p>This is the code I tried,</p>
  </blockquote>
  
  <pre><code>var fm = Ext.form;
  var grid = new Ext.grid.EditorGridPanel({
      height: 500,
      renderTo: Ext.getBody(),
      width: 800,
      loadMask: false,
      viewConfig: {
          emptyText: 'No data to display'
      },
      selModel: checkboxselection,
      tbar: mainGridToolbar,
      clicksToEdit: 1,
      store: cartStore,
      listeners: {
          afteredit: function(o) {
  
              var pos = o.record.get('POS');
              var quantity = o.value;
  
          }
      },
      columns: [
          checkboxselection,
          {
              header: "quantity",
              align: 'right',
              dataIndex: 'QUANTITY',
              sortable: true,
              editor: new fm.TextField({
                  allowBlank: false
              })
          }
      ]
  });
  </code></pre>