Assume you have one radio group name default_lang and you want to know which one is selected
<input name=”default_lang” value=”en” type=”radio” />
<input name=”default_lang” value=”fr” type=”radio” />
<input name=”default_lang” value=”de” type=”radio” />
Well, it’s easy with jQuery
var default_lang = $('input:radio[name=default_lang]:checked').val();