EXT弹出框缺边少框现象

var data = [["1","2"],["1","2"]];

    var ds = new Ext.data.ArrayStore({
        fields:[{name:'machinename'},{name:'machinevalue'}],
        data: data
    })

    var grid = new Ext.grid.GridPanel({bodyStyle:'width:100%', height:200,columns:[
            {header:'名称',dataIndex:'machinename',align:'center',sortable:true},
            {header:'值',dataIndex:'machinevalue',align:'center',sortable:true,width:280}
        ],store:ds})

    this.grid = grid;

    this.dwin = new Ext.Window({
        title:this.text+'机器配置',
        layout:'fit',
        width:420,
        height:200,
        closable:true,
        closeAction:'hide',
        resizable:true, 
        plain: true,
        items:[grid]
    })
    this.click = function(){
        this.dwin.show();
    } 

我的代码如上,设计的是点击按钮就调用this.click,按理说可以显示一个带有表格的弹出框,但是出来的就是缺边少框的
下面分别是ie6与火狐中弹出框的显示情况

css文件的路径没有对.如果路径对了那就是和css相关的image资源没有复制到工程