尝试在Suitescript 2.0中创建库存收据，保留错误field.getSublistName

Question

我尝试通过自定义记录类型进行库存收据。基本过程是采购订单将创建自定义记录类型，然后自定义记录类型将创建物料收货记录。有我的代码。

function saveRecord(scriptContext) {

    var curRec = scriptContext.currentRecord;
    var poId = curRec.getValue({
        fieldId : 'custrecord_qms_insp_source_doc'
    });

    var itemId = curRec.getValue({
        fieldId : 'custrecord_qms_insp_item'
    });

    var poRec = record.load({
        type : record.Type.PURCHASE_ORDER,
        id : poId
    });

    var itemReceipt = record.transform({
        fromType : record.Type.PURCHASE_ORDER,
        fromId : poId,
        toType : record.Type.ITEM_RECEIPT,
        isDynamic : false
    });

    itemReceipt.setValue({
        fieldId : 'exchangerate',
        value : 1
    });

    itemReceipt.setValue({
        fieldId : 'customform',
        value : 39
    });

    var today = new Date();

    itemReceipt.setValue({
        fieldId : 'trandate',
        value : today
    });

    itemReceipt.setSublistValue({
        sublistId : 'item',
        fieldId : 'location',
        line : 0,
        value : 4
    });

    itemReceipt.setSublistValue({
        sublistId : 'item',
        fieldId : 'quantity',
        line : 0,
        value : 2
    });

    var itemSubrecord = itemReceipt.getSublistSubrecord({
        sublistId : 'item',
        line : 0,
        fieldId : 'inventorydetail'
    });

    itemSubrecord.insertLine({
        sublistId : 'inventoryassignment',
        line : 0
    });

    itemSubrecord.insertLine({
        sublistId : 'inventoryassignment',
        line : 0
    });

    itemSubrecord.setSublistValue({
        sublistId : 'inventoryassignment',
        fieldId : 'quantity',
        line : 0,
        value : 2
    });

    itemReceipt.save();

}

return {
    saveRecord : saveRecord
};

当我运行它时，它一直显示错误消息："TypeError: field.getSublistName is not a function"。我不知道为什么显示此消息以及如何解决它。任何帮助将不胜感激。