EXT gridPanel 添加图片

var workAreaGrid = new Ext.grid.GridPanel({
            region: 'west',
            title: '工作面预警结果',
            store: wkSto,
            width: ,
            split: true,
            margins: "0 3 0 0",
            stripeRows: true,
            autoExpandColumn: '',
            //            loadMask: {
            //                msg: '正在加载数据，请稍侯……'
            //            },
            columns: [new Ext.grid.RowNumberer(), {
                header: 'ID',
                hidden: true,
                width: ,
                dataIndex: 'ID'
            },
            {
                header: 'intClassBJ',
                hidden: true,
                width: ,
                dataIndex: 'BJ'
            },
            {
                header: 'intClassYJ',
                hidden: true,
                width: ,
                dataIndex: 'YJ'
            },
            {
                header: '工作面名称',
                width: ,
                dataIndex: 'chrWorName'
            },
            {
                header: '时间',
                width: ,
                dataIndex: 'date'
            },
            {
                header: '采掘工艺',
                width: ,
                dataIndex: 'GX'
            },
            {
                header: '状态预警',
                width: ,
                dataIndex: 'intClassBJ',
                renderer: function (record) {
                    var str;
                    switch (record.toString()) {
                        case "": str = "<img src=\"SubSystem/WSFT_System/resources/Imgs/0.jpg\"/>";
                            break;
                        case "": str = "<img src=\"SubSystem/WSFT_System/resources/Imgs/1.jpg\"/>";
                            break;
                        case "": str = "<img src=\"SubSystem/WSFT_System/resources/Imgs/2.jpg\"/>";
                            break;
                    }
                    return str;
                }
            },
            {
                header: '趋势预警',
                width: ,
                dataIndex: 'intClassBJ',
                renderer: function (record) {
                    var str;
                    switch (record.toString()) {
                        case "": str = "<img src=\"SubSystem/WSFT_System/resources/Imgs/0j.jpg\"/>";
                            break;
                        case "": str = "<img src=\"SubSystem/WSFT_System/resources/Imgs/1j.jpg\"/>";
                            break;
                        case "": str = "<img src=\"SubSystem/WSFT_System/resources/Imgs/2j.jpg\"/>";
                            break;
                    }

                    return str;
                }
            }],
            listeners: {
                celldblclick: function (grid, rowIndex, record) {

                    //alert(record.toString());
                }
            }
        });