brigz,
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title></title>
</head>
<body>
<form id="form" name="form" method="post" action="">
<div>
<input type="checkbox" name="apname" id="apCheckDis" onclick="myfunc()" checked="checked">
</div>
<div id="new" style="display:none">
<input type="radio" name="atname" value="0">
<input type="radio" name="atname" value="1">
</div>
</form>
<script type="text/javascript">
function myfunc() {
if (document.form.apname.checked == true) {
document.getElementById('new').style.display = "block";
} else{
document.getElementById('new').style.display = "none";
}
}
myfunc()
</script>
</body>
</html>