<script type="text/javascript" charset="utf-8" src="https://rawgithub.com/nulrich/ncanvas/master/dist/ncanvas.js"></script>
<canvas id="myCanvas"></canvas>
var myCanvas = $nc(document.getElementById("myCanvas"));
// Create a rectangle
var rect = myCanvas.rect(20, 20, 80, 80, {fillStyle:"darkBlue"});
// Refresh canvas to display new objects
myCanvas.repaint();