Html5's canvas doesn't show anything
<p>I am testing html5's canvas and nothing is there, even though I display rectangles.
What could be wrong?</p>

<p>My code is
canvas.js</p>

<pre><code>var CV = CV || {};
CV.initialize = function()
{
    console.log('start');
    cv = $('#canvas')[0];

    canvas = cv.getContext('2d');
    canvas.strokeRect(10, 10, 100, 150);
    canvas.fillRect(10, 200, 100, 150);
    canvas.clearRect(20, 200, 50, 50);
};
</code></pre>

<p>index.html</p>

<pre><code>&lt;html&gt;
    &lt;head&gt;
        &lt;title&gt;Canvas tutorial&lt;/title&gt;
        &lt;meta charset="UTF-8"&gt;
        &lt;meta name="viewport" content="width=device-width, initial-scale=1.0"&gt;

    &lt;/head&gt;
    &lt;body&gt;
        &lt;section id="main"&gt;
            &lt;canvas id="canvas" width="600" height="400"&gt;
                Hopefull you see this, if not get a real browser
            &lt;/canvas&gt;            
        &lt;/section&gt;




        &lt;!-- JAVASCRIPT --&gt;
        &lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"&gt;&lt;/script&gt;
        &lt;script src="js/canvas.js" type="text/javascript"&gt;&lt;/script&gt;
        &lt;script&gt;
            $(document).ready(function(){
                Cv.initialize();
            });
        &lt;/script&gt;
        &lt;!-- END JAVASCRIPT --&gt;
    &lt;/body&gt;
&lt;/html&gt;
</code></pre>

<p>jsfiddle is <a href="https://jsfiddle.net/Thomas_nyan/tj1bnqr8/2/" rel="nofollow">here</a>.</p>

<p>Thanks</p>