请教！获取json数据的方法

[xyy7309]

<script type="text/javascript">
<!--
var xmlhttp;
// 创建XMLHTTPRequest对象
function createXMLHTTPRequest()
{
if(window.ActiveXObject)//②如果当前浏览器为IE
{
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
else if(window.XMLHTTPRequest)//③如果是其他浏览器
{
xmlhttp = new XMLHTTPRequest();
}
}

function getInfo()
{
var name =document.getElementById("name").value;

createXMLHTTPRequest();
var url ="a.asp?u="+name;
xmlhttp.open("get", url, true);
xmlhttp.onreadystatechange = returnInfo;
xmlhttp.send(null);
}

function returnInfo()
{
if(xmlhttp.readyState == 4)
{
var info = xmlhttp.responseText;
shownr.innerHTML = info;
}
}
-->
</script>

用xmlhttp.responseText 方法读取到返回json格式的数据：
info = {"user_a":{"user":{"nick":"您好","sex":"男","user_id":888888}}}

请教大侠！ 如何分别获取？ 如下：

shownick.innerHTML = nick;
showsex.innerHTML = sex;
showuid.innerHTML = user_id;

[似梦飞花]

info = {"user_a":{"user":{"nick":"您好","sex":"男","user_id":888888}}}; var d=info.user_a.user; shownick.innerHTML = d.nick; showsex.innerHTML = d.sex; showuid.innerHTML = d.user_id;