title: How do I retrieve an element with a specific ID from another webpage?
body: <p>I am trying to retrieve the value of an element with a certain ID from another webpage. I know that to retrieve an element on the same page is:  </p>
  
  <pre><code>document.getElementById("thingy1");
  </code></pre>
  
  <p>Is there a way to input an address and id, and return a value?</p>