<!DOCTYPE html>
<html>
<body style="zoom: 1.5">
  <p>An all green square should appear below</p>
  <canvas id="A" width=300 height=300></canvas>
  <script type="text/javascript" charset="utf-8">
    var context = document.getElementById("A").getContext("2d");
    context.fillStyle = 'green';
    context.fillRect(1, 1, 298, 298);   
  </script>
</body>
</html>