RESTlet POST Invoice

Below is the RESTlet, the sample one given by NetSuite. I test the the RESTlet with a customer and it works. I am trying to modify so it will create an invoice and therefore needs to add a line item as well. I am trying to get this to work but as of now it says that the item is an invalid reference key, which it is valid

I think I need to work on parsing out the nested JSON array.

Sorry I just keep on working on this and trying to update this as I go along.

              if (value && typeof value != 'object') // ignore other type of parameters               {                   record.setFieldValue(fieldname, value);               }               else {                   record.setLineItemValue('item', fieldname, 1, value)         // insert the line item in the RESTlet              }