如何在javascript获得表单中单选按钮的值?

[rcrain]

如何在javascript获得表单中单选按钮的值?
<input type="radio" name="flag" value="Y" >
是
<input type="radio" name="flag" value="N" >
否</td>

我怎么在javascript中活动值呢？怎么用flag.value取不到值呢？

[clare2003]

<input type="radio" id="flag1" name="flag0" value="Y" ID=Radio1>
是
<input type="radio" id="flag2" name="flag0" value="N" ID=Radio2>
否</td>
<script>
alert(document.all.flag1.value);
</script>

[clare2003]

<input type="radio" name="flag" value="Y" >
是
<input type="radio" name="flag" value="N" >
否</td>
<script>
alert(document.all.flag[0].value);
</script>

[treeroot]

var radio=document.all.flag;
var value=null;
if(radio.length){
for(var i=0;i<radio.length;i++){

}
else if(radio.checked) {
value=radio.value;
}

[treeroot]

var radio=document.all.flag;
var value=null;
if(radio.length){
for(var i=0;i<radio.length;i++){
if(radio[i].checked) {value=radio[i].value;break;}
}

}
else if(radio.checked) {
value=radio.value;
}

[clare2003]

function Init()
{
var obj=document.all.div1;
for(var i=0;i<10;i++)
{
var sel=document.createElement("<SELECT NAME='mySel' id='selid0'><SELECT>");
sel.add(new Option("--selected--","--selected--"));

// sel.name="mySel";
addoption(obj,sel);

sel.onchange=function()
{

[clare2003]

发错了!