Hi
Try like this..
<script type="text/javascript">
function maxlen() {
var rb = document.getElementById("<%=rbtnPloicyType.ClientID%>");
var inputs = rb.getElementsByTagName('input');
var flag = false;
var selected;
for (var i = 0; i < inputs.length; i++) {
if (inputs[i].checked) {
selected = inputs[i];
flag = true;
break;
}
}
if (flag)
alert(selected.value);
}
</script>