把如下代码加入<body>区域中
<script Language="javascript">
function a(x,y,color)
{document.write("<img border='0' style='position: absolute; left: "+(x+300)+"; top: "+(y+200)+";background-color: "+color+"' src='px.gif' width=1 height=1>")}
</script>
<script>
for(t=1;t<=360;t++){
lo=200 * Math.sin(2 * (Math.PI / 180) * t);
x = lo * Math.cos((Math.PI / 180) * t);
y = lo * Math.sin((Math.PI / 180) * t);
a(x,y,"#000000");
lo=200 * Math.cos(2 * (Math.PI / 180) * t);
x = lo * Math.cos((Math.PI / 180) * t);
y = lo * Math.sin((Math.PI / 180) * t);
a(x,y,"#ff0000");
}
</script>
