NetSuite Mass Update script runs sucessfully, but nothing gets updated - netsuite

Question

Have been a developer for years, but just getting into NetSuite scripting. I wanted to start simple and create a script that would update the COMMENT field for all items on a purchase order. I started off by following the tutorial found here.
My modified script is below - it should update the MEMO field at the PO header and then every line's COMMENT field. I followed the steps in the article to save the script, create a Mass Update and then run it. In my criteria I set: "Transaction Number/ID" and "has keyword 90999" (just so it would only run on one specific purchase order). I confirmed my criteria was correct by clicking "Preview" and it only returns that one PO.
When I run the Mass Update, it runs fine and says it has been run successfully on 1 record (which is good). The MEMO field at the PO header DOES get updated, but the COMMENT field for each line does not. Am I doing something wrong or missing something simple? Is the getLineCount call not the correct one to use?
Note that I was doing all this in our Sandbox environment in case that makes any difference
UPDATE:
I know the getLineCount call is returning the correct number because if I move the poRec.setValue call inside the for loop, it gets run. So something must be wrong with my poRec.setSublistValue call?
/**
*#NApiVersion 2.0
*#NScriptType MassUpdateScript
*/
define(['N/record'],
function (record) {
function each(params) {
// Need to LOAD each record and SAVE it for changes to take effect
// LOAD the PO
var poRec = record.load({
type: params.type,
id: params.id
});
//var mainDepartment = poRec.getValue('department');
var mainDepartment = 'Hello World';
poRec.setValue({
fieldId: 'memo',
value: mainDepartment
});
// get a count of the line items
var lineCount = poRec.getLineCount({
sublistId: 'item'
});
// go through each of the line items and set the department to the main level department
for (var i = 0; i < lineCount; i++) {
poRec.setSublistValue({
sublistId: 'item',
fieldId: 'comment',
line: i,
value: mainDepartment
});
}
// SAVE the PO
poRec.save();
}
return {
each: each
};
});

Answer 1

There is no 'comment' field on the item sublist. The field you probably mean is 'description' (which expresses on searches as the line level 'memo' field - Netsuite for the win!)