extjs grid分页效果不出来数据

Ext.BLANK_IMAGE_URL='ext/resources/image/default/s.gif';

Ext.onReady(function(){

  
    var store = new Ext.data.JsonStore({
        root: 'topics',
        totalProperty: 'totalCount',
        idProperty: 'threadid',
        remoteSort: true,

        fields: [
            'title', 'forumtitle', 'forumid', 'author',
            {name: 'replycount', type: 'int'},
            {name: 'lastpost', mapping: 'lastpost', type: 'date', dateFormat: 'timestamp'},
            'lastposter', 'excerpt'
        ],

      
       proxy: new Ext.data.ScriptTagsProxy({url:'http://extjs/fdfdf/we.jsp'})

    });
    store.setDefaultSort('lastpost', 'desc');

 

如果改为url:'localhost:8080/we.jsp就看不到数据为什么，怎么改呢