Hi there cinci-hal,
Our friend Vic supplied a solution whilst I was preparing mine. 
One minor difference in mine is that, I hide the form from those with javascript disabled.
I also remove event handlers from the HTML.
[color=navy]
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>untitled document</title>
<style>
#container {
width:960px;
margin:auto;
}
.hide{
display:none;
}
#frmOptions label {
cursor:pointer;
}
</style>
<script>
(function() {
'use strict';
function init(){
document.getElementById('frmOptions').className='';
var obj=document.getElementById('dvArea');
var inp=document.getElementById('frmOptions').getElementsByTagName('input');
var c=inp.length;
while(--c>-1) {
inp[c].number=c;
inp[c].onclick=function(){
this.number==0?obj.className='':obj.className='hide';
}
}
}
window.addEventListener?
window.addEventListener('load',init,false):
window.attachEvent('onload',init);
})();
</script>
</head>
<body>
<div id="container">
<form id="frmOptions" class="hide">
<input type="radio" name="options" id="opt0" checked="checked">
<label for="opt0">Option 1</label>
<input type="radio" name="options" id="opt1" >
<label for="opt1">Option 2</label>
</form>
<div id="dvArea">
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec
ultricies sollicitudin nisi, ut molestie felis adipiscing sit
amet. Sed auctor vehicula commodo. Nam a nibh neque, vitae
faucibus felis. Vivamus at metus eget eros consequat fringilla.
Quisque magna magna, laoreet eu tempus sit amet, fringilla at
tellus. Praesent felis tortor, scelerisque vitae fringilla
non, porttitor et lacus. Ut ut sapien nec quam tincidunt
consectetur in nec lacus.
</p>
</div>
</div>
</body>
</html>[/color]
coothead
