javascript - access radio button value through form id -

i working on website several forms of radio buttons, 1 of this:

<form id = "configuration">     <ul>         <li><input type="radio" name="configuration" id="0" value="0"/> gt manual</li>         <li><input type="radio" name="configuration" id="1" value="1"/> gt automatic</li>     </ul> </form> 

is there way (javascript) can access value of radio buttons directly, e.g.

var value = document.getelementbyid("configuration").configuration.value; 

(here first "configuration" form id while second 'configuration' name, rather looping through each element in form check button selected?

thank you!

get this...

var radios = document.getelementsbyname('configuration');  (i = 0; < radios.length; i++) {     if (radios[i].type == 'radio' && radios[i].checked) {         alert(radios[i].value);     } }