I would go about setting the radio buttons up in some kind of an array if possible and using the if statement to say something like this, which you will need to heavily modify to your form fields and code.
if (form == yes)
{
openWindow()
}
Now I have used a function, although it being 5am for me I may have made a syntax error so I would check it through before implementing it into your site, now I will show you basically how to code the function, although you will need to modify it to your properties.
<script type="text/javascript">
<!--
function openWindow() {
window.open("", "newwin", "height=300,width=300");
}
//-->
</script>
Theres the function, however you could also use onClick method, I think although I have never experimented it on radio buttons it may be possible.