title: When button is submitted it returns a 404 error?
body: <p>Here is my code.</p>
  <p>Adding both the HTML and Javascript to get a clear understanding of what I did so someone can see where I went wrong</p>
  <p>HTML</p>
  <pre><code>&lt;form id=&quot;form&quot; onsubmit=&quot;return addUser()&quot;&gt;
  &lt;h2&gt;Add a User:&lt;/h2&gt;
  &lt;input id=&quot;name&quot; type=&quot;text&quot; name=&quot;username&quot; placeholder=&quot;name&quot;&gt;
  &lt;input id=&quot;email&quot; class=&quot;mail&quot; type=&quot;email&quot; name=&quot;email&quot; placeholder=&quot;email&quot; onkeydown=&quot;validate()&quot;&gt;
  &lt;span id=&quot;text&quot;&gt;&lt;/span&gt;
  &lt;button type=&quot;submit&quot;&gt;Add User&lt;/button&gt;
  &lt;h2&gt;Users:&lt;/h2&gt;
  &lt;ul id=&quot;users&quot;&gt;&lt;/ul&gt;
  &lt;/form&gt;
  </code></pre>
  <p>Javascript</p>
  <p>It works fine in my local environment but when submitted in jsfiddle it returns a 404 error</p>
  <pre><code>function validate() {
     let form = document.getElementById('form');
     let email = document.getElementById('email').value
     let eData = /^(([^&lt;&gt;()[\]\.,;:\s@\&quot;]+(\.[^&lt;&gt;()[\]\.,;:\s@\&quot;]+)*)|(\&quot;.+\&quot;))@(([^&lt;&gt;()[\]\.,;:\s@\&quot;]+\.)+[^&lt;&gt;()[\]\.,;:\s@\&quot;]{2,})$/i;
     let text = document.getElementById('text')
     
     if (email.match(eData)) {
     form.classList.add('valid')
     form.classList.remove('invalid')
     text.innerHTML = &quot;Your Email is Valid&quot;
     text.style.color = 'green'
     } else {
     form.classList.remove('valid')
     form.classList.add('invalid')
     text.innerHTML = &quot;Please Enter Valid Email&quot;
     text.style.color = 'red'
     }
     
     if (email == '') {
     form.classList.remove('valid')
     form.classList.remove('invalid')
     text.innerHTML = ''
     text.style.color = '#00e5ff'
     }
  }
  
  const list = document.getElementById('users')
  
  function addUser() {
  let newName = document.getElementById('name').value
  let newMail = document.querySelector('.mail').value
  let data = document.createElement('li')
  data.appendChild(document.createTextNode(newName + ' ' + newMail))
  list.appendChild(data)
  return false;
  }
  
  // END YOUR CODE HERE
  
  
  </code></pre>
  <p>jsfiddle for reference</p>
  <p><a href="http://jsfiddle.net/m3c5djbf/25/" rel="nofollow noreferrer">http://jsfiddle.net/m3c5djbf/25/</a></p>