js_form_validation

//html
<form id="quiz_form" action="?page={{ qn_page.next_page_number }}" method="post" >
 <! --my form elemements here -->
 <input type="submit" class="btn btn-primary btn-large" value="Next Question">
</form>

//js
$(function(){
        //validate quiz form

        $('#quiz_form').submit(function (e) {
          validate_quiz_form(e);
      });

    });

function validate_quiz_form(e){
      e.preventDefault();
      var len = $('#quiz_form input:radio:checked').length;
      if (!len) {
        alert("None checked");
        return;
      }
      $("#quiz_form").submit();
      //$(this).submit();
    }
//chrome console
Uncaught RangeError: Maximum call stack size exceeded