title: How to get radio button to display alert message
body: <p>I want to get a radio button to display an alert when it is selcted, so the user can check that they have chosen the correct value. This is the code I have for the radio buttons:</p>
  
  <pre><code> &lt;tr&gt;
       &lt;td&gt;&lt;input type="radio" name="level" id="GCSE" value="GCSE"&gt;GCSE&lt;br&gt;
      &lt;input type="radio" name="level" id="AS" value="AS"&gt;AS&lt;br&gt;
      &lt;input type="radio" name="level" id="A2" value="A2"&gt;A2&lt;/td&gt;
   &lt;/tr&gt;
  </code></pre>
  
  <p>How would I get so when any of these radio buttons are selected an alert is displayed to the user saying: "Are you sure you have chosen the correct entry level?"</p>
  
  <p>Please keep answers simple, as I have only been learning HTML for 3 weeks</p>