脚本小问题！！
<script>
function asb()
{
alert(document.userinfo.aas.value)
}
</script>



<form name=userinfo method=post action=>
<input name= "aas " type= "radio " value= "aas " checked />
<input name= "aas " type= "radio " value= "ssss " />
<input name= " " type= "submit " value= "提交 " onclick= "asb() " />
</form>

为什么提交后出现“undefined”


[解决办法]
function asb()
{
var list = document.userinfo.aas;
if(list.length){
for(var i=0;i <list.length;i++) if(list[i].checked){alert(list[i].value);break;}
}
else alert(list.value);
}