I am attempting to add event listeners to all of the buttons in an HTML document. When a button is pressed I'd like to display a simple alert.
My code, which isn't working at the moment, follows:

var bns = document.getElementsByTagName(button);



function addtoev() {

  for (i = 0; i < bns.length; i++) {

    bns[i].addEventListener(click, function() {

        alert(you clicked); 

    });

   }

}

It definitely works as such in JSFiddle by calling the method or eliminating the function line, but it's still not executing in Chrome (popups are not blocked). I post my HTML, is it possible that buttons nested in a table need to be referenced differently than buttons alone?

  <tr>

  <td>John</td>

  <td>Doe</td>

  <td>[email protected]</td>

   <td><button class=btn btn-default>X</button></td>

  </tr>