HTML5 Canvas绘制指定坐标线条的实现

<!DOCTYPE html>
<html>
<body>
<canvas id="myCanvas" width="200" height="100"
style="border:1px solid #c3c3c3;">
Your browser does not support the HTML5 canvas tag.
</canvas>
<script type="text/javascript">
var c=document.getElementById("myCanvas");
var ctx=c.getContext("2d");
ctx.moveTo(10,10);
ctx.lineTo(150,50);
ctx.lineTo(10,50);
ctx.stroke();
</script>
</body>
</html>