title: setCustomValidity is not a function
body: <p>This is the simple code I run hoping to get control over html5 validation but the browser says <code>setCustomvalidity</code> is not a function. what am I doing wrong?</p>
  <pre class="lang-html prettyprint-override"><code>&lt;!doctype html&gt;
  &lt;html&gt;
  &lt;head&gt;
      &lt;meta charset=&quot;utf-8&quot;&gt;
      &lt;title&gt;Untitled Document&lt;/title&gt;
      &lt;meta http-equiv=&quot;X-UA-Compatible&quot; content=&quot;IE=edge,chrome=1&quot;&gt;
      &lt;meta http-equiv=&quot;Content-Type&quot; content=&quot;text/html; charset=utf-8&quot;&gt;
      &lt;script src=&quot;https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js&quot;&gt;&lt;/script&gt;
  &lt;/head&gt;
  
  &lt;body&gt;
      &lt;input type='text' id='tocheck' /&gt;
      &lt;script&gt;
          $(&quot;#tocheck&quot;).click(function () {
              var $this = $(this);
              $this.setCustomValidity(&quot;slkdjf&quot;);
          });
      &lt;/script&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>