javascript to hide prompt button based on radio button selection

[smtest]

Hi all,
I am trying to hide prompt button(next, cancel or reprompt) based on radio button selections. I am having problems reading the values of radio button, i know how to read using list box but now radio button. for list i am using this code:document.forms["formWarpRequest"].elements["_oLstChoicesUID1"].value;

pls advice
thanks