title: Iframe does not read the text
body: <p>I uploaded the html file and image file(png) into the Sharepoint for chatbot html file. When I insert text into iframe it's not reading the text.</p>
  
  <blockquote>
    <p>Uncaught DOMException: Failed to read the 'cssRules' property from 'CSSStyleSheet': Cannot access rules
    Error:Uncaught TypeError: Cannot read property 'value' of null at onChange.</p>
  </blockquote>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>// Get the modal
  var newmodal = document.getElementById('myModal');
  
  // Get the button that opens the modal
  var btn = document.getElementById("myBtn");
  
  // Get the &lt;span&gt; element that closes the modal
  var span = document.getElementsByClassName("close")[0];
  
  // When the user clicks the button, open the modal 
  btn.onclick = function() {
    newmodal.style.display = "block";
  }
  // When the user clicks on &lt;span&gt; (x), close the modal
  span.onclick = function() {
    newmodal.style.display = "none";
  }</code></pre>
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.newmodal {
    width: 300px;
    background-color: lightgray;
    position: fixed;
    bottom: 50px;
    right: 38px;
    display: none;
  }
  
  img {
    background: white;
    position: fixed;
    bottom: 15px;
    right: 15px;
    height: 60px;
    width: 60px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"&gt;
  &lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"&gt;&lt;/script&gt;
  &lt;script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"&gt;&lt;/script&gt;
  
  &lt;div class="container-fluid"&gt;
    &lt;div class="newmodal" id="myModal"&gt;
      &lt;div class="close-btn"&gt;
        &lt;span class="close"&gt;&amp;times;&lt;/span&gt;
      &lt;/div&gt;
  
      &lt;iframe height="400" width="300" src='myiframelink'&gt;&lt;/iframe&gt;
    &lt;/div&gt;
    &lt;img id="myBtn" src="https://sharepoint.com....."&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>