title: Why canvas doesn't work with jQuery selector?
body: <p>I have made simple example of using canvas and then I saw that my code doesn't work when I use jQuery selector.</p>
  
  <p><strong>Examples:</strong></p>
  
  <p><a href="http://jsfiddle.net/cXXdP/4/" rel="noreferrer">Javascript</a></p>
  
  <pre><code>    window.onload = function() {
          var canvas = document.getElementById('myCanvas');
          var ctx = canvas.getContext('2d');
  
          ctx.fillRect(10,50,100,200);
      };
  </code></pre>
  
  <p><a href="http://jsfiddle.net/46VKa/2/" rel="noreferrer">JQuery</a></p>
  
  <pre><code>   window.onload = function() {
          var canvas = $('#myCanvas');
          var ctx = canvas.getContext('2d');
  
          ctx.fillRect(10,50,100,200);
      };
  </code></pre>
  
  <p>So I have no idea why it happened. Is there any limitations about it?</p>