纯JavaScript实现弹出选择第几个单选按钮

纯JavaScript实现弹出选择第几个单选按钮

<div id="a" name="aa"> 
    <input type="radio" name="aab" value="22" /> 
    <input type="radio" name="aab" value="22" /> 
    <input type="radio" name="aab" value="22" /> 
    <input type="radio" name="aab" value="22" /> 
</div>

<script type="text/javascript"> 
    var list = document.getElementById("a").children; 
    for (var i = 0; i < list.length; i++) { 
        list[i].attributes["index"] = i + 1; 
        list[i].onclick = function () { 
            alert(this.attributes["index"]); 
        } 
    } 
</script>