title: Highlight.js in textarea
body: <p>So i have been struggeling to use highlight.js in a text area since obviously this doesn't work:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
  &lt;title&gt;Hello World&lt;/title&gt;
  &lt;link rel="stylesheet" href="styles/default.css"&gt;
  &lt;script src="highlight.pack.js"&gt;&lt;/script&gt;
  &lt;script&gt;hljs.initHighlightingOnLoad();&lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;form&gt;
      JavaScript Injection: &lt;br&gt; 
  &lt;pre&gt;
  &lt;code&gt;
  &lt;textarea name="js_execute" cols="50" rows="10" "&gt;&lt;/textarea&gt;
  &lt;/code&gt;
  &lt;/pre&gt;
  &lt;input type="button" name="Inject_Execute_Button" value = "Inject" onclick="executeJS()" &gt;
  &lt;/form&gt;
  
  &lt;script type="text/javascript"&gt;
   function executeJS()
   {
       alert("Wohoo");
   }
  &lt;/script&gt;
  
  
  &lt;style type ="text/css"&gt;
  
  &lt;/style&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>I'm pretty sure there's an easy answer to this so i won't explain it in too detail but at the end i would prefer to have code typed into the textarea highlighted in JavaScript.</p>