title: How to remove all listeners in an element?
body: <p>I have a button, and I added some <code>eventlistners</code> to it:</p>
  
  <pre><code>document.getElementById("btn").addEventListener("click", funcA, false);
  document.getElementById("btn").addEventListener("click", funcB, false);
  document.getElementById("btn").addEventListener("click", funcC, false);
  document.getElementById("btn").addEventListener("blur" , funcD, false);
  document.getElementById("btn").addEventListener("focus", funcE, false);
  
  &lt;button id="btn"&gt;button&lt;/button&gt;
  </code></pre>
  
  <p>I can remove them by:</p>
  
  <pre><code>document.getElementById("btn").removeEventListener("click",funcA);
  </code></pre>
  
  <p>What if I want I want to remove all listeners at once, or I don't have the function reference (<code>funcA</code>)? Is there a way of doing that, or I have to remove them one by one?</p>