JSFiddle - React, Tailwind, and code Playground

HTML

<form method="post" id="form">
  <fieldset>
    <legend>Grade Exams</legend>
    <ul>
      <li>
        <p>Barrister's Exam</p>
        <label>
          <input type="radio" name="barrister" value="1" /> Pass
        </label>
        <label>
          <input type="radio" name="barrister" value="0" /> Fail
        </label>
      </li>  
      <li class="submit">
        <input type="button" id="check" value="Test">
      </li>
    </ul>
  </fieldset>
</form>

JavaScript

$(function(){
  // Submit form via ajax
  $('#check').click(function(){
    var barrister = null
    $.each($("input[name='barrister']:checked"), function(){
      if($(this).val() == 1)
        barrister = $(this).attr('value');
    });
    if(barrister){
      $.ajax({
        type: "POST", url: "http://yearofcall.com/wp-content/plugins/myplugin/results.php", 
        data: "action=insert&barrister=" + barrister,
        complete: function(data){
          messageList.html(data.responseText);
          updateShoutbox();
      
          //reactivate the send button
          $("#send").attr({ disabled:false, value:"Send" });
        }
      });
    } else {
      alert('Please fill all fields!')
    }
      
  })
})