ExtJs 给grid某一单元格重新赋值

// 司机，搬运工提成
var commissionMoney = (waybillsFtQty * commissionMoneyRatio / personCount).toFixed(2);
// 重置配载列表司机与帮运工提成
for (var i = 0; i < planGrid.getStore().getCount(); i++) {
    var record = planGrid.getStore().getAt(i);
    record.set('commissionMoney',commissionMoney);
    record.commit();
}