ETX.JS GRID

Question

        function fetch() {
            var dcountry = "", dstate = "",strpas="";
            dcountry = document.getElementById('PCountry').value;
            dstate = document.getElementById('Pstate').value;
            strpas = "cntry=" + dcountry + "&stt=" + dstate;
            var recordType = new Ext.data.Record.create([
                                                            { name: "Partner_Name", type: "string" },
                                                            { name: "Custs", type: "string" },
                                                            { name: "NetPrice", type: "string" },
                                                            { name: "ListPrice", type: "string" },
                                                            { name: "Discount", type: "string" },
                                                            { name: "AvgSpend", type: "string" },
                                                            { name: "Units", type: "string" }
                                                            ]);
            var reader = new Ext.data.JsonReader({ totalProperty: "results", root: "rows", id: "number" }, recordType);
            var proxy = new Ext.data.HttpProxy({ url: './GetData.ashx' });
            var ds = new Ext.data.Store({ proxy: proxy, reader: reader });
            var storeParams = { params: { start: 0, limit: 10, pas: strpas} };  //分页参数
            remoteSort: true;
            ds.load(storeParams);
            var sm = new Ext.grid.CheckboxSelectionModel(); 
            var cm = new Ext.grid.ColumnModel( {
                                                    defaultSortable : true,  
                                                    columns : [ 
                                                    sm,
                                                    { header: '<center>Partner Name</center>', dataIndex: 'Partner_Name', width: 100 },
                                                    { header: '<center>Custs</center>', dataIndex: 'Custs', width: 200 },
                                                    { header: '<center>Booking</center>', dataIndex: 'NetPrice', width: 80 },
                                                    { header: '<center>ListPrice</center>', dataIndex: 'ListPrice', width: 200 },
                                                    { header: '<center>Discount</center>', dataIndex: 'Discount', width: 50 },
                                                    { header: '<center>AvgSpend</center>', dataIndex: 'AvgSpend', width: 70 },
                                                    { header: '<center>Units</center>', dataIndex: 'Units', width: 60 } 
                                                    ] 
                                                    });             
            var pagingBar = new Ext.PagingToolbar({
                pageSize: 10,
                store: ds,
                displayInfo: true,
                displayMsg: 'Display Record {0} - {1} of {2}',
                emptyMsg: "No results to display",
                items: ['-']
            });
            var grid = new Ext.grid.GridPanel({
                cm: cm,
                ds: ds,
                title:'TestGrid',
                frame: false,
                border: true,
                layout: "fit",
                loadMask: { msg: 'Loading...' },
                autoWidth: false,
                autoHeight: false,
                autoScroll: true,
                stripeRows: true,
                autoExpandColumn: 'id', //自动扩展列宽
                trackMouseOver: true, 
                height: 350,
                width : 500,
                title : 'Data列表',
                region: 'center',
                bbar : pagingBar
            });
            grid.render();
这是我写的ETX.GRID JS代码,为什么执行不到GetData.ashx文件呢?