How is a joined field returned in nlapiLookupField?

Curious before performing this myself.

If I have multiple fields being looked up and one or more of them are joined fields, how are these returned in the results associative array/object?

For example:

   var myFields = ['field1','field2','joined.field1','joined.field2'];  var results = nlapiLookupField(recdtype,recdid,myFields);  // assume access direct fields as:  var val = results.field1;  val = results.field2;  // how would I access the joined field array???  val = results.joined.field1; // like this? or  val = results['joined.field1']; // like this? 

Thanks.
-Steve