Can someone tell me why radiofield event is not triggered in Extjs4 MVC?

I tried:
'viewport > casesearch > radiofield'
'viewport > casesearch radiofield'

I also tried the line below which returned all 8 radiofields on the panel. So the code should know the radiofields are there.
Ext.ComponentQuery.query('casesearch > radiofield');

Thanks


controller:
Code:
        this.control({
            //'casesearch button'   :{                                  //working for all button
            'casesearch button[id=searchbtnimage_id]'   :{                
                click: this.onCaseSearchBtnClick               ////working
            } ,
             'casesearch > radiofield' :     //none working
             {
                uncheck : function(data){ alert("abc1"); },
                checked : function(data){ alert("abc2"); },
                handler : function(data){ alert("abc3"); },
                click : function(data){ alert("abc4"); },
                change : function(data){ alert("abc5"); }
             }

        });
View:

Code:
Ext.define('SC.view.case_search.Case_search', {
    extend: 'Ext.panel.Panel',
    alias : 'widget.casesearch',    
    id:  'casesearch_id',
    title: 'case search',
    
    initComponent: function() {
  
        this.callParent(arguments);
    },

    items: [
        {                
            items: [  
                 { 
                    xtype: 'fieldcontainer',    //simplified.  In real case, this is in a fieldset which is on a panel.
                    fieldLabel : 'user', 
                    defaultType: 'radiofield',   
                    layout: 'column',
                    items: [   
                        {
                            id: 'rd_loginname_0a',
                            boxLabel  : 'all cases'
                            name      : 'FilterLoginName',
                            columnWidth: .2    
                        },
                        {
                            id: 'rd_loginname_1a',
                            boxLabel  : 'my cases only',
                            name      : 'FilterLoginName',
                            columnWidth: .3    
                        }
                    ]  
                 }
            ]            
        }
    ]
});