In vendor bills I am trying to find duplicates of a vendor / invoice combination when the user enters the bill number (ie. reference no.). The idea is to be alerted that there is a possible duplicate before any other data entry is done. In the below script I am getting an Unexpected Error but am not sure why. It seems to me that the issue is with the search but am not sure what it could be. Any ideas?

/**
        *@NApiVersion 2.0
        *@NScriptType ClientScript
        */
        define(['N/record','N/search', 'N/ui/dialog'], function (r,search,u) {
            function fieldChanged(context) {
        var recCurrent = context.currentRecord;            
                if((context.fieldId == 'tranid')) {
                    var vendorinvoice = recCurrent.getValue({
                        fieldId: 'tranid'
                    });
                    var vendor = recCurrent.getValue({ fieldId: 'name'});
                    console.log(vendorinvoice);
            var sv = search.create({
            type: "vendorbill",
                columns : [
                    search.createColumn({name: "internalid", label: "Internal ID"})
                 ],

                filters : [
                    ["type","anyof","VendBill"], 
                    "AND", 
                    ["mainline","is","T"], 
                    "AND", 
                    ["name","anyof",vendor], 
                    "AND", 
                    ["tranid","is",vendorinvoice]
                 ] 
            });
            
            var pagedData = sv.runPaged({pageSize: 1000});
            
            var printOnce = 0;
            for (var i = 0; i < pagedData.pageRanges.length; i++) {
    
                // fetch the current page data
                var currentPage = pagedData.fetch(i);
                // and forEach() thru all results
                currentPage.data.forEach(function(result) {
    
                    // you have the result row. use it like this....
                    var duplicate = result.getValue('internalid');
                    console.log(duplicate);
                    if (duplicate && printOnce==0) {
                        printOnce++;
                        alert('This vendor / vendor invoice combination already exists.')
                    }
                });
    
            }

            }
        }
        return {
                    fieldChanged: fieldChanged
        };
            });

the usual is to pay attention to the stack trace on the thrown error

thanks, found the issue. for vendor bills need to use entity not name for the vendor.