http://www.walterzorn.de/en/dragdrop/demos/frameset/frame.htm

<html>
<head>
<title>Cross-Frame Communication with wz_dragdrop.js</title>
</head>
<frameset cols="50%, 50%">
  <frame name="left" src="left.htm">
  <frame name="right" src="right.htm">
</frameset>
</html>