<?xml version="1.0" encoding="utf-8"?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Canvas drag and drop: helper file</title>
<style type="text/css">
div
  {width:20px;
  height:20px;
  background-color:green;}
body
  /* Center the div in this iframe since we know the iframe size (it's fixed
  * in the parent page to 'width:300px; height:200px;') */
  {margin-top:90px;
  margin-left:140px;}
</style>
<script type="application/ecmascript">
function start(event)
  {event.dataTransfer.effectAllowed