var canvas = document.getElementById('cv');
canvas.width = 400;
canvas.height = 300;
var context = canvas.getContext('2d');
context.fillStyle = "black";
context.font = "50px Arial";
context.fillText('ASD', 0, 50);
context.globalCompositeOperation = "destination-over";
context.fillStyle = "#00FFFF";
context.fillRect(0,0,canvas.width,canvas.height);//for white background
context.globalCompositeOperation = "source-over";
context.lineWidth = 2;
context.strokeStyle="#FF0000";
context.strokeRect(0, 0, canvas.width, canvas.height);//for white background