how to get radio button value in javascript--

[selvialagar]

my code doesn't work. undefined is displayed.....how to get a value of radoi button in javascript

[HTML]function enableaddr()
{
alert(document.getElementById('reason').length);
for (var i=0; i < document.getElementById('reason').length; i++)
{
if (document.getElementById('reason[i]').checked)
{
var reason1 = document.getElementById('reason[i]').value;
alert(reason1);
}
}
}

<form action="cust_index.php?action=delete&cid=<?php echo $cid;?>" name="del_form">
<table width="400" border="0" cellpadding="6" align="center" cellspacing="1" class="bg1">
<tr class="bg2"><td>Enter the reason to delete the record with the customer name <?php echo $name;?> :</td></tr>
<tr class="bg2"><td><input type="radio" name="reason" id="reason" value="close" onclick="enableaddr()" />Close</td></tr>
<tr class="bg2"><td><input type="radio" name="reason" id="reason" value="shifta" onclick="enableaddr()" />Shift &nbsp;</td></tr>
<tr class="bg2"><td>Enter the address :&nbsp;&nbsp;&nbsp;<textarea cols="30" rows="4" disabled="disabled" name="shiftaddress" id="shiftaddress"></textarea></td></tr>
<tr class="bg2"><td align="center"><input type="submit" value="submit" class="button"></td></tr>
<input type="hidden" name="reason1" id="reason1" />
</table>
</form>[/HTML]

[gits]

you make the wrong use of getElementById(). first, the id HAS TO be unique in a page ... and so the method could give you just ONE element. you may use something that retrieves you a node list like in the following example:

function enableaddr() {
    var reasons = document.getElementsByName('reason');
 
    for (var i = 0; i < reasons.length; i++) {
        if (reasons[i].checked) {
            var reason1 = reasons[i].value;
            alert(reason1);
        }
    }
}
 

kind regards