<html>
 <head>
 <style>
 div { background: -webkit-canvas(squares); width:600px; height:600px; border:2px solid black }
 </style>
 
  <script type="application/x-javascript">
function draw(w, h) {
 var ctx = document.getCSSCanvasContext("2d", "squares", w, h);

 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);
}
  </script>
 </head>
 <body onload="draw(300, 300)">
   <div></div>
 </body>
</html>