title: Toggle class to an element by click another element
body: <p>I want to click on an element to toggle a class being referenced on a completely unrelated element (not a child, parent or sibling)</p>
  
  <p>For example, initially the code would look like this</p>
  
  <pre><code>&lt;a id="button"&gt;Button&lt;/a&gt;
  
  &lt;div class="navigation"&gt;
  Foo
  &lt;/div&gt;
  </code></pre>
  
  <p>When the user clicks the element with the id <code>button</code> the HTML would change to look like this (the class "open" is referenced on element with "navigation" already referenced":</p>
  
  <pre><code>&lt;a id="button"&gt;Button&lt;/a&gt;
  
  &lt;div class="navigation open"&gt;
  Foo
  &lt;/div&gt;
  </code></pre>
  
  <p>The user should be able to toggle the class by clicking the element with the id <code>button</code>.</p>
  
  <p>I would like to use pure javascript to achieve this effect.</p>