Canvas fillText and clear
HTML
<body>
<canvas id="myCanvas" width="810" height="512" style="border:1px solid #d3d3d3;">
Your browser does not support the HTML5 canvas tag.</canvas>
<p><strong>Note:</strong> The canvas tag is not supported in Internet Explorer 8 and earlier versions.</p>
</body>
JavaScript
var message = "Hello world";
var canvas = document.getElementById("myCanvas");
var context = canvas.getContext("2d");
context.fillText("New text",100,100);