Web Forms :: Clearing A RadioButtonList With Javascript?

I'm posting this here because my question isn't really about the javascript itself but about the workings of the RadioButtonList control. I have a webforms application where a several radiobuttonlist controls are rendered dynamically from server side code. I want to also render an undo button that will clear the associated radiobuttonlist. I can get it to work fine using an image button that does a postback. However, I'd like to do it without the postback, waiting until the entire form is filled out before posting back via a submit button. I've been able to get it to clear the radio buttons via javascript. However, when I click submit to post back to the server, the server thinks the radiobutton is still selected. Here's a condensed version of the code thatrenders the controls.

[Code]....

At run time, the radiobuttonlists and their associated undo buttons are rendered just fine. If the user selects an option from a radiobuttonlist and then decides they didn't want to answer that question, they can click the undo button and in the browser the correct radiobuttonlist is cleared. However, when they submit, it still saves whatever value they had clicked before to the database. It's as if there is something else on the page that is holding on to the selected value in the radiobuttonlist even after the javascript clears the control itself.