A copy of the JavaScript functions in the head element:

// sample-1-radio-button-processing.js
// This sample shows processing of radio buttons.

// onload set the body's color and background color
function loaded()
  {

  // reset division colors
  var my_div = document.getElementById("my-div");
  my_div.style.color = "green";
  my_div.style.backgroundColor = "white";

  // reset checked in all input elements (which are all radio button)
  var my_form = document.getElementById("my-form");
  for(var i=0; i < my_form.childNodes.length; i++)
    {
    if(my_form.childNodes[i].nodeName == "INPUT")
      {
      my_form.childNodes[i].checked = false;
      }
    }
  }

// onclick copy radio button color and backgroundColor to the div
// the selected radio button object is passed as the argument
function color_radio_function(e)
  {
  var my_div = document.getElementById("my-div");
  my_div.style.color = e.style.color;
  my_div.style.backgroundColor = e.style.backgroundColor;
  }