Deselect all values on a single select radio button in a stateless form based on a button click

Deselect all values on a single select radio button in a stateless form based on a button click

Hi,

I'm trying to allow a user to erase their answer to a question on a radio button field. The user is answering many questions displayed one at a time using a stateless form. I reload the form to go from one question to the next. 

In this case, the user wants to go back to an answered question and erase their answer after realizing they are not sure of the correct answer. 

I'm trying to do this using a button on the form. The following commands had no effect:
  1. rdAnswer= null;
and 
  1. rdAnswer= "";

I tried 
  1. rdAnswer.deselect(rdAnswer);
and 
  1. rdAnswer.deselectall();
and got an error: "rdAnswer can be used only in on load actions"

If I make the field a Dropdown the user could choose the "-Select-" value to erase their selection, but the correct representation is Radio button.