nlapiSearchRecord causing "_funcname is not defined" error

here's the code:

function consignmentSearchSales()
{
alert("searching...");
var filters = new Array();
filters[0] = new nlobjSearchFilter( 'custitem_vendor', 'item', 'anyof', 'Hypo Recordings');
var columns = new Array();
columns[0] = new nlobjSearchColumn( 'internalid' );
var searchresults = nlapiSearchRecord( 'invoice', null, filters,  columns );
//var searchresults = nlapiSearchRecord('transaction', 13, null,  null );

alert ("?: " + searchresults);
return true;
}

the function is triggered by a custom button the purchase order form.

i get the first alert ("searching...") so i know that the function is getting triggered. (then getting the error). The second alert never gets triggered (due to the error)

The end result is to find all the transactions that contained consignment items (for each consignment vendor such as 'Hypo Recordings') and then generate PO's for those items.)