<html>
<head>
</head>
<frameset rows="20%,60%,*">
<frame src="top.html" />
<frameset cols="20%,*">
<frame src="mid_left.html" />
<frame src="mid_right.html" />
</frameset>
<frame src="bottom.html" />
</frameset>
</html>
程序运行结果为
