title: How to Disable or hide checkbox for specific rows Grid with CheckboxModel
body: <p>I have a grid with check-box model and I want to disable some of the check-boxes on certain condition. </p>
  
  <ol>
  <li>Don't want to use renderer to override the DOM element.</li>
  <li><p>Want to do something like this.....</p>
  
  <pre><code>grid.getStore().load({          
    scope: this,          
    callback: function(records, operation, success) {            
      if (success) {              
        var sm = grid.getSelectionModel();              
        Ext.each(records, function(record) {                
          if (record.data.chkd) {
            var row = record.index;
            // console.log(record.index);                  
            sm.select(row, true);                  
            // HERE WANT TO DISABLE THE CHECKBOX FOR THE PARTICULAR RECORD
          }
        });              
      } else {              
        //alert(success);
        //console.log(operation.exception);
      }
    }
  });
  </code></pre></li>
  </ol>
  
  <p>Thanks in advance for your help!!</p>