title: How can I get the id in Extjs checkcolumn?
body: <p>Im tiro in Extjs.</p>
  
  <p>That is my model:</p>
  
  <pre><code>Ext.define('CatModel', {
      extend: 'Ext.data.Model',
      idProperty: 'id',
       fields: [{
          name: "name",
          convert: undefined
      }, {
          name: "id",
          convert: undefined
      }]
  }); 
  </code></pre>
  
  <p>store:</p>
  
  <pre><code>var store = Ext.create('Ext.data.TreeStore', {
      model:'CatModel',
      root: {
          expanded: true
      },
      proxy: {
          type: 'ajax',
          reader: 'json',
          url: 'item_access.jsp?fullpage=true&amp;show_cat=1'
      }
  });
  </code></pre>
  
  <p>and treePanel:</p>
  
  <pre><code>var treePanel = Ext.create('Ext.tree.Panel', {
      id: 'tree-panel',
      title: 'Sample Layouts',
      region:'north',
      split: true,
      height: 560,
      minSize: 150,
      rootVisible: false,
      autoScroll: true,
      store: store,
      columns: [
          {
              xtype: 'treecolumn',
              text: 'name',
              flex: 2.5,
              sortable: true,
              dataIndex: 'name'
          },
          {
              text: 'id',//I want to get this id
              flex: 1,
              dataIndex: 'id',
              sortable: true
          }
          , {
              xtype: 'checkcolumn',
              text: 'Done',
              dataIndex: 'done',
              width: 55,
              stopSelection: false,
              menuDisabled: true,
              listeners:{
                  checkchange:function(cc,ix,isChecked){
                      //alert(isChecked);
                      //I want to get this row id in here 
                  }
              }
          }]
  });
  </code></pre>
  
  <p>In <code>checkchange</code> function there are three parameter one unknown,two is index, and three is check status ...</p>
  
  <p>So how can I get the the same row id where I check the checkbox??</p>
  
  <p>Can I find that id number by checkbox row index??</p>