title: How to access parent dom element from child iframe?
body: <p>parent domain is </p>
  
  <pre><code>example.com/abc/
  </code></pre>
  
  <p>and the iframe's domain is </p>
  
  <pre><code>abcd.example.com/hhh/.
  </code></pre>
  
  <p>is it possible to access the dom element of parent?</p>