Getting the selected value of an ASP.NET Radiobuttonlist from javascript

            var radioButtons = document.getElementById('<%=rdbpayment.ClientID%>');
            var inputs = radioButtons.getElementsByTagName("input");
            var selected;
            for (var i = 0; i < inputs.length; i++) {
                if (inputs[i].checked) {
                    selected = inputs[i];
                    break;
                }
            }
            if (selected) {
               alert(selected.value);
            }