<html>
<head>
<title>frame test</title>
</head>
<frameset cols="50%,*">
  <frame src="about:blank" name="frame1">
  <frameset rows="50%,*">
    <frame src="about:blank" name="frame2">
    <frame src="about:blank" name="frame3">
  </frameset>
  <noframes>
  Please see by the browser corresponding to the frame.
  </noframes>
</frameset>
</html>