title: evt argument inside a function in javaScript
body: <h2>evt argument inside a function in javaScript</h2>
  
  <p>Hello stackoverflow community.
  I need to know how is the <strong>evt</strong> argument used in these functions.
  There are some examples in the internet which have the argument evt inside of a function, but I don't see them using the argument.</p>
  
  <pre><code>document.getElementById("creator").addEventListener("click", function(evt){
      alert("created");
  });
  
  document.getElementById("change").addEventListener("click", function(evt){
      alert("changed");
  });
  </code></pre>
  
  <p>I guess the evt argument is just set as undefined because those functions are never called with a value for the argument.</p>
  
  <ul>
  <li>So what is the reason for setting the argument variable evt?</li>
  <li>can it be hello instead of evt?</li>
  <li>if it is predefined to the event listeners, how can I find a list of
  predefined arguments?</li>
  </ul>