刚学extJS，怎么按照教程写出的脚本无法运行

Ext.onReady(function(){

    var store = new Ext.data.Store({
        data : [
            [1,'Office Space','Mikie Judge','1992-02-19',1,'Work Sucks','19.95',1],
            [3,'Supper Troopers','Jay Chandrasekhar','2002-02-15',1,'Altered State Police','14.95',1]
        ],
        reader : new Ext.data.ArrayReader({id,'id'}, 
            ['id','title','director',
                {
                   name:'released',
                   type:'date',
                   dateFormat:'Y-m-d'
                },'genre','tagline','price','available'
            ]
        )
    });

    store.load();

    var grid = new Ext.grid.GridPanel({
        renderTo:Ext.getBody(),
        frame:true,
        title:'Movie Database',
        height:200,
        width:500,
        store:store,
        columns:[
             {header:"Title",dataIndex:'title'},
             {header:"Director",dataIndex:'director'},
             {header:"Released",dataIndex:'released',renderer:Ext.util.Format.dateRenderer('m/d/Y')},
             {header:"Genre",dataIndex:'genre'},
             {header:"Tagline",dataIndex:'tagline'}
         ]
    });
});

在jsp中调用下，或者将这段代码加载到jsp的scrip里， 你写的renderTo:Ext.getBody(),意思是将grid渲染到（生成到）jsp/html的body的元素上显示