var memoSearch = search.lookupFields({
                        type: search.Type.CREDIT_MEMO,
                        id: tranid,
                        columns: ['custbody_affiliate_transaction', 'unapplied']
                    });

I’m doing a lookup fields on a credit memo, but when I add

unapplied

to it I get the following error:

An nlobjSearchColumn contains an invalid column, or is not in proper syntax: unapplied.