title: Javascript how to pass variable and set color
body: <p>I have two textarea</p>
  
  <pre><code>&lt;textarea id="area1"&gt;Hello how are you&lt;/textarea&gt;
  &lt;textarea id="area2"&gt;&lt;/textarea&gt;
  </code></pre>
  
  <p>I want pass area1 value to area2 and show, then set  "Hello" to color red, "how are you" to color green</p>
  
  <pre><code>var area1=document.getElementById("area1");
  var area2=document.getElementById("area2");
  </code></pre>
  
  <p>How to do this in JavaScript? thank you</p>