title: Can regular JavaScript be mixed with jQuery?
body: <p>For example, can I take this script (<a href="https://developer.mozilla.org/en/Canvas_tutorial:Basic_usage" rel="noreferrer">from mozilla tutorial</a>):</p>
  
  <pre><code>&lt;html&gt;
   &lt;head&gt;
    &lt;script type="application/javascript"&gt;
      function draw() {
        var canvas = document.getElementById("canvas");
        if (canvas.getContext) {
          var ctx = canvas.getContext("2d");
  
          ctx.fillStyle = "rgb(200,0,0)";
          ctx.fillRect (10, 10, 55, 50);
  
          ctx.fillStyle = "rgba(0, 0, 200, 0.5)";
          ctx.fillRect (30, 30, 55, 50);
        }
      }
    &lt;/script&gt;
   &lt;/head&gt;
   &lt;body onload="draw();"&gt;
     &lt;canvas id="canvas" width="150" height="150"&gt;&lt;/canvas&gt;
   &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>and mix this JavaScript with jQuery's document.ready instead of relying on onload?</p>