i am trying to set a background image to a list...i can get it working with panel. but it does not work with list.

Code:
Bollist.js

Ext.define('tabla.view.Bollist',
    {
        extend:'Ext.Panel',
        xtype:'Bollist',
        config:{
            title:'Bols',
            iconCls:'music2',
            layout:'fit',
            styleHtmlContent:true,
            scrollable:{
                direction:'vertical'
            },
            items:[
                {
                    xtype:'list',
                    store:'BolStore',
                    itemTpl:'{name}'
                }
            ]
        }
    });

Main.js

Ext.define("tabla.view.Main", {
    extend: 'Ext.tab.Panel',
    requires: [
        'Ext.TitleBar',
        'Ext.dataview.List'
    ],
    config: {
        tabBarPosition: 'bottom',


        items: [
            {
                style:{
                    backgroundImage:'url(resources/images/bg.png)',
                    backgroundRepeat:'repeat',
                    backgroundPosition:'center',
                    backgroundSize:'cover'
                },
                xtype:'home'
            },
            {
                style:{
                    backgroundImage:'url(resources/images/bg.png)',
                    backgroundRepeat:'repeat',
                    backgroundPosition:'center',
                    backgroundSize:'cover'
                },
                xtype:'Bollist'
            }
        ]
    }
});
Help appreciated please... I need to submit my assignment.