ExtJs在LOAD的时候就出错? 急该如何处理

function addLoadEvent(fn) {        if (typeof win.addEventListener != UNDEF) {            win.addEventListener("load", fn, false);        }        else if (typeof doc.addEventListener != UNDEF) {            doc.addEventListener("load", fn, false);        }        else if (typeof win.attachEvent != UNDEF) {            addListener(win, "onload", fn);        }        else if (typeof win.onload == "function") {            var fnOld = win.onload;            win.onload = function() {                fnOld();                fn();            };        }        else {            win.onload = fn;        }    }

Ext.onReady(function() {    var gridDtl;    var myStore = new Ext.data.JsonStore({        autoLoad: true,        proxy: new Ext.data.HttpProxy({            url: 'PttGetData.asmx/qryCancelableById',            headers: { 'Content-type': 'application/json' }        }),        baseParams: { id: 'aa' },        root: 'd',        fields: ['TermId', 'MsgTime', 'CardId', 'SimNo', 'ShiftSN', 'CmdType', 'CmdMsg', 'IsSucc', 'T_isRec', 'T_IsCommit', 'SendTime', 'RecvTime', 'CommitTime']    });    var grid = new Ext.grid.GridPanel({        store: myStore,        columns: [                               { header: "信息收发时间", width: 300, renderer: rendeDate, dataIndex: 'MsgTime' },                               { header: "终端号", width: 150, dataIndex: 'TermId' },                               { header: "车牌号", width: 150, dataIndex: 'CardId' },                               { header: "终端sim卡号", width: 200, dataIndex: 'SimNo' },                               { header: "作业流水号", width: 200, dataIndex: 'ShiftSN', sortable: true },                               { header: "命令类型", width: 150, dataIndex: 'CmdType', sortable: true },                               { header: "命令信息内容", width: 200, dataIndex: 'CmdMsg', sortable: true },                               { header: "收发是否成功", width: 200, dataIndex: 'IsSucc', sortable: true },                               { header: "终端是否收到", width: 200, dataIndex: 'T_isRec', sortable: true },                               { header: "终端是否人工确认", width: 200, dataIndex: 'T_IsCommit', sortable: true },                               { header: "下发时间", width: 300, renderer: rendeDate, dataIndex: 'SendTime', sortable: true },                               { header: "接收时间", width: 300, renderer: rendeDate, dataIndex: 'RecvTime', sortable: true },                               { header: "人工确认时间", width: 300, renderer: rendeDate, dataIndex: 'CommitTime', sortable: true }                    ],        viewConfig: { forceFit: true },        width: 1280,        height: 250,        split: true,        buttons: [{ text: '核销', handler: OnCav}],        renderTo: 'CAV',        frame: true    });    function rendeDate(record) {        var strDate = "new " + record.substr(1, record.length - 2)        return eval("(" + strDate + ")").toLocaleString();    }});