document.write('
解析:
<!DOCTYPE html>
<html>
<body>
<canvas id="myCanvas" width="200" height="200"
style="border:2px solid blue;">
您的浏览器不支持。
</canvas>
<script type="text/javascript">
var c=document.getElementById("myCanvas");
var cxt=c.getContext("2d");
cxt.fillStyle="#FF0000";
cxt.beginPath();
cxt.arc(100,100,75,0,Math.PI*2,true);
cxt.closePath();
cxt.fill();
</script>
');