extjs wait for second tab to be created?

FoxyOrders.panel.Home = function(config) {
    config = config || {};
	
	Ext.apply(config,{
        border: false
        ,baseCls: 'modx-formpanel'
        ,cls: 'container'
        ,items: [{
            html: '<h2>Foxy Orders</h2>'
            ,border: false
            ,cls: 'modx-page-header'
        },{
            xtype: 'modx-tabs'
            ,defaults: { border: false ,autoHeight: true }
            ,border: true
            ,items: [{
                title: 'Pending Orders'
                ,defaults: { autoHeight: true }
                ,items: [{
                    html: '<div id="pending_orders"><p>Loading Orders...</p></div>'
                    ,border: false
                    ,bodyCssClass: 'panel-desc'
                }]
            },{
                title: 'Completed Orders'
                ,defaults: { autoHeight: true }
                ,items: [{
                    html: '<div id="completed_orders"><p>Loading Orders...</p></div>'
                    ,border: false
                    ,bodyCssClass: 'panel-desc'
                }]
			}]
        }]
    });
    FoxyOrders.panel.Home.superclass.constructor.call(this,config);
	
	
	
};
Ext.extend(FoxyOrders.panel.Home,MODx.Panel);
Ext.reg('foxyorders-panel-home',FoxyOrders.panel.Home);

	
var pending_orders = function (response) {
	pending_message = Ext.get('pending_orders');
	pending_message.update(response.responseText);
}

var completed_orders = function (response) {
	completed_message = Ext.get('completed_orders');
	completed_message.update(response.responseText);
}

Ext.Ajax.request({
   url: '/assets/components/foxyorders/pending.php',
   success: pending_orders,
   failure: function () { console.log('failure');}
});

Ext.Ajax.request({
   url: '/assets/components/foxyorders/completed.php',
   success: completed_orders,
   failure: function () { console.log('failure');}
});

,listeners: {
            render: function(grid) {   
               var mask = new Ext.LoadMask(this.getEl(),{msg:_('loading')});
               mask.show();                   
               var store = grid.getStore();
               store.on('load', function() {
                   var summary = store.reader.jsonData.summary;
                   Ext.get('evo-booking-total-bkgs').update(summary.totalBkgs);
                   Ext.get('evo-booking-total-cost').update(summary.totalCost);
                   Ext.get('evo-booking-total-due').update(summary.totalDue);
                   mask.hide();
               }, grid);
            }
        }