title: Avoiding memory leaks winjs EventListeners
body: <p>I want to know if I add an event listener to a button, do I have to remove it on <code>unload</code>? Would pressing the 'back' button automatic removes everything current page elements in which I don't need to worry about memory leaks?</p>
  
  <pre><code>(function () {
  "use strict";
  ui.Pages.define("/pages/registraton/registraton.html",{
      ready: function (element, options) {
          document.getElementById("submitRegister").addEventListener(
              "click", postRegistration , false);
  
      },
      unload: function () {
          document.getElementById("submitRegister").removeEventListener(
         "click", postRegistration, false);
      }
  });...
  </code></pre>
  
  <p>Thanks in advance.</p>