How to get radio buttn list value in Js?

if

<input name="sex" id="sex_male" type="radio" value="male">
<input name="sex" id="sex_female" type="radio" value="female">

Then

var theRadioGroup=getRadioValue("sex")

function getRadioValue(theRadioGroup)
{
    var elements = document.getElementsByName(theRadioGroup);
    for (var i = 0, l = elements.length; i < l; i++)
    {
        if (elements[i].checked)
        {
            return elements[i].value;
        }
    }
}




2nd
<script>
function getRadioValue()
{
    for (var i = 0; i < document.getElementsByName('sex').length; i++)
    {
    	if (document.getElementsByName('sex')[i].checked)
    	{
    		return document.getElementsByName('sex')[i].value;
    	}
    }
}
</script>


function getCheckedValue(radioObj) {
        if (!radioObj)
            return "";
        var radioLength = radioObj.length;
        if (radioLength == undefined)
            if (radioObj.checked)
                return radioObj.value;
            else
                return "";
        for (var i = 0; i < radioLength; i++) {
            if (radioObj[i].checked) {
                return radioObj[i].value;
            }
        }
        return "";
    };