title: How to display an html file in javascript?
body: <p>I am trying to display an html file in my js-code. </p>
  
  <p>It is an ordinary html file that I would like to see. I have already created an IFRAME for this, but somehow I cannot go further...</p>
  
  <p>This is my code fragment:</p>
  
  <pre><code>var controlAddIn = document.getElementById('controlAddIn').src = 'index.html';
  </code></pre>
  
  <p>So the file I want to call is "index.html". But it is not working.</p>
  
  <p>If I call it in that way:</p>
  
  <pre><code>var controlAddIn = document.getElementById('controlAddIn').srcdoc = '&lt;div&gt;&lt;meta charset="UFT-8"&gt;&lt;meta name="viewport" content="width=device-width, initial-scale=1.0"&gt;&lt;/div&gt;';
  </code></pre>
  
  <p>It is working, but taht makes it very hard to read...
  Do you have an idea, how I can call my entire code at this point, also multiline?</p>