michael@0: function createCanvas() {
michael@0:   var canvas = document.createElement("canvas");
michael@0:   canvas.setAttribute("width", 100);
michael@0:   canvas.setAttribute("height", 100);
michael@0:   var ctx = canvas.getContext("2d");
michael@0:   ctx.fillStyle = "rgb(200,0,0)";
michael@0:   ctx.fillRect(10, 10, 55, 50);
michael@0:   ctx.fillStyle = "rgba(0,0,200,0.5)";
michael@0:   ctx.fillRect(30, 30, 55, 50);
michael@0:   return canvas;
michael@0: }