Using JQuery to check if no radio button in a group has been checked

Question

I\'m sitting with a problem, I need to check with JQuery if no radio button within a radio button group has been checked, so that I can give the users an javascript error if

Answer 1

var len = $('#your_form_id input:radio:checked').length;
      if (!len) {
        alert("None checked");
      };
      alert("checked: "+ len);