nlapiSubmitRecord() gives an error! Pls help...

Hi
I have a server script that creates a new custom record, when another custom record is created/edited.  I get the following error:

Notice (SuiteScript)
 
Invalid reference key [null].
 
I tried the debugger and the error get triggered at the nlapiSubmitRecord() line.  an extract of my code is below:

var alhistory = nlapiCreateRecord('customrecordal_history');
alhistory.setFieldValue('custrecordalh_employee', req);
alhistory.setFieldValue('custrecordalh_type', 2);
alhistory.setFieldValue('custrecordalh_description', "Approved AL Request");
alhistory.setFieldValue('custrecordalh_noofdays', newRecord.getFieldValue('custrecordal_days'));
alhistory.setFieldValue('custrecordalh_enteredby', app);
alhistory.setFieldValue('custrecordalh_dateupdated', newRecord.getFieldValue('custrecordal_approvaldate'));
alhistory.setFieldValue('custrecordalh_al', 5);
alhistory.setFieldValue('custrecordalh_closingbalance', 10);