Suitescript 2.0 - Filter List Of Customers in Suitelet 'Select' Field

Hi,

I have a Suitescript 2.0 Suitelet that I'm working on and am attempting to add a simple select field with the source as the 'customer' List/Record.  It works fine until I try and filter the list of customers and populate it via .addSelectOption.

Seems like it's not happy for me to call customerField.addSelectOption even though I know the suitescript 1.0 equivalent used to work fine..??

Any help on this would be greatly appreciated..

Here's the error:

 {      "type": "error.SuiteScriptError",      "name": "SSS_INVALID_UI_OBJECT_TYPE",      "message": "That operation is not supported for this type of UI object: select. It is only supported for type: select."  }