ExtJs 給grid某一單元格重新賦值

// 司機，搬運工提成
var commissionMoney = (waybillsFtQty * commissionMoneyRatio / personCount).toFixed(2);
// 重置配載列表司機與幫運工提成
for (var i = 0; i < planGrid.getStore().getCount(); i++) {
    var record = planGrid.getStore().getAt(i);
    record.set('commissionMoney',commissionMoney);
    record.commit();
}