js下获得单选框的值的代码

<form name="myform"> <div> <input name="point" type="radio" value="是" checked>是</div> <div> <input name="point" type="radio" value="否">否</div> <input type="button" value="确定" onclick="get_radio_value(myform.point);"> </form>
[ctrl+a 全选 注:如需引入外部js需刷新才能执行]