Code
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="myCanvas" width="200" height="100" style="border:1px solid #d3d3d3;">
Trình duyệt này không hỗ trợ phần tử canvas.
</canvas>
<script>
var i=0;
function draw_line(){
var c=document.getElementById("myCanvas");
var ctx=c.getContext("2d");
ctx.moveTo(0,0);
if(i<200)
i++;
else
return;
ctx.lineTo(i,i/2);
ctx.stroke();
setTimeout("draw_line();",50);
}
draw_line();
</script>
</body>
</html>