如何用JavaScript显示两个点之间的直线（或者说画出这条直线）？

参考下面的代码：<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office"><style>
v\:* { behavior: url(#default#VML) }
o\:* { behavior: url(#default#VML) }
shape { behavior: url(#default#VML) }
</style>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>柱状图</title>
<body>
<script language="JavaScript" type="text/javascript">
<!--
var o=document.createElement("v:group");
o.style.width="800";
o.style.height="500";
o.coordsize="21600,21600";
o.style.position="absolute"; var line=document.createElement("v:line");
line.style.position="relative";
line.style.left="10%";
line.style.top="2%";
line.style.flip="x";
line.from="0,0";
line.to="0,20000";
line.title = "hahah";o.appendChild(line);
document.body.appendChild(o);
//-->
</script>
</body>
</html>