Using Check box to filet grid
===

I have a groupCheck box implemented. When i click on it I will be displaying a console message displaying the value of it. When i uncheck it i get `undefined`, which eventually gives me trouble later on. I am trying to filter my grid based on this values. i will be adding this value to an array, and when i uncheck the checkbox i get `undefined` and finally end up with an error : `TypeError: array is undefined [Break On This Error] return array.indexOf(item, from);`


     items: [
                                            {
                                                xtype: 'checkboxgroup',
                                                height: 100,
                                                width: 399,
                                                layout: {
                                                    align: 'stretch',
                                                    type: 'vbox'
                                                },
                                                fieldLabel: '',
                                                items: [
                                                    {
                                                        xtype: 'checkboxfield',
                                                        name: 'chk',
                                                        boxLabel: 'ONE',
                                                        inputValue: 'ONE',
                                                        flex: 1
                                                    }
                                                ],
                                                listeners: {
                                                    change: {
                                                        fn: me.onCheckboxgroupChange1,
                                                        scope: me
                                                    }
                                                }
                                            }
                                        ]
                                    },....



the action event -- `onCheckboxgroupChange1`

    onCheckboxgroupChange: function(field, newValue, oldValue, options) {
            console.log("Value == "+newValue.tasktypecheckbox);
        var chksel=newValue.taskstatuscheckbox;


    var s= Ext.getStore('Person');
  
    s.clearFilter();
    s.on('load', function() {
        s.filter({
            filterFn: function(r) {
                return Ext.Array.indexOf(chksel, r.get('school')) > -1;

            }
        });
    }, this, { single: true });
      

        s.load(); 
    }