title: .on() doesn't work on appended element(jQuery)
body: <p>So I'm appending a row in a table and then upon clicking a button I want to remove that row.
  However I can't do it in a way that seems natural, like:</p>
  
  <pre><code>$(".usun").on("click", function(){
      $(this).parent().parent().remove();
  });
  </code></pre>
  
  <p>where <code>.usun</code> is a class of buttons that remove a row in a table. Of course this fragment of code is inside of <code>$(document).ready(...</code>. What seems to work for me is this:</p>
  
  <pre><code>$(this).on("click", ".usun", function(){ 
      $(this).parent().parent().remove();
  });
  </code></pre>
  
  <p>and I don't understand why. Could someone explain me this?</p>