JQuery中如何得到radio的值

<!-- BEGIN show_count_bore --><label>
  <input type="radio" name="count_bore" value="{count_bore}" class="count_bore" {count_bore_checked}>
  {count_bore_value}&nbsp;</label>
  <!-- END show_count_bore -->

当点击radio单选进行选择是得到所单选的value

$(function(){
  $(".count_sink").click(function(){
    alert($("input[name='count_sink']:checked").val())

    }) 
});