如何给editorgrid中的某列赋值???

JScript code

listeners: { select: function(combo, record, index) {
        var id = record.data.companyid;
        Ext.Ajax.request({
            url: '../../DATA/diaodu/GetRegions.aspx',
            method: "POST",
            params: {
                companyid: id
            },
            success: function(response) {
                var tmp = response.responseText.split("|"); var regionid = tmp[0];
                grid_add.store.each(function(record) { record.set("qyd", regionid); });
            }
        });
    }
    }

关键是这行 grid_add.store.each(function(record) { record.set("qyd", regionid); });
应该是不能用循环
但是应该怎么赋值?