var INVITATION_CODE_DEFAULT_VALUE = 'You need a invitation code';

        $(document).ready(function() {
            var elem = $('#invitationCode');
            elem.focus(function() {
                resetInvitationCode();
            });
            elem.blur(function() {
                load();
            });
            load();
  $('form').submit(function(){
    if($('#age_check:checked').length == 1){
      alert('Only people 13 years old and older may use this website. Please ask your parent or an adult to help you use this site.');
      return false;
    }
  })
        });
        function load() {
            var elem = $('#invitationCode');
            if (elem.val() == "")
                elem.val(INVITATION_CODE_DEFAULT_VALUE);
        }
        function resetInvitationCode() {
            var elem = $('#invitationCode');
            if (elem.val() == INVITATION_CODE_DEFAULT_VALUE) {
                elem.val("");
            }
        }
        function sign_up() {
            resetInvitationCode();
            $("#new_user").submit();
        }