title: Adding members to an existing object
body: <p>Suppose we have the following object:</p>
  
  <pre><code>var obj = {
      fn1: function() {
      }
  }
  </code></pre>
  
  <p>how can I dynamically add another member to it, say</p>
  
  <pre><code>fn2: function() {}
  </code></pre>