title: I want to call a function when an element no longer has a specific class (no jquery)
body: <p>I am making a plugin for a site where I can only use javascript. I want to execute code when il element with id = "gridview" no longer has the "hidden" class. Thank you for your help.</p>
  
  <p>I already tried:</p>
  
  <pre><code>document.getElementById("id="eval_grid_tab"").addEventListener("click", start);  
  </code></pre>
  
  <p>This is the html</p>
  
  <pre><code>&lt;li id="eval_grid_tab"&gt;&lt;a href="#gridview"&gt;Tabel&lt;/a&gt;&lt;/li&gt;
  &lt;div id="gridview" class="rightsPanel smscTabsPanel hidden" style="height: 795px;"&gt;...&lt;/div&gt;
  </code></pre>