Snippet Library

function getSetRadio(obj) { // P2 is optional and implies we are Setting
         for (var i=0; i < obj.length; i++) {
             if (arguments.length > 1) { // we are setting
                if (arguments[1] == null) {
                    obj[i].checked = false;
                } else
                if (obj[i].value == arguments[1]) {
                    obj[i].checked = true;
                    return true;
                }
             } else { // we are getting
                if (obj[i].checked) return obj[i].value;
             }
         }
         return false;
}

<!---Body--->

 
<form name="myForm">
  <input type=radio name="gender" value="Boy">Male<br>
  <input type=radio name="gender" value="Girl">Female<br>
</form>


var sex = getSetRadio(myForm.gender) // retu\r\ns "Boy", "Girl", or false
getSetRadio(myForm.gender,"Boy") // selects Male
getSetRadio(myForm.gender,null)  // unselects all.