<?xml version="1.0" encoding="utf-8"?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Adding element to datastore on dragover</title>
<style type="text/css">
span, strong
	{color:green;
	background-color:yellow;}
strong
	{color:red;}
div
	{width:100px;
	height:100px;
	background-color:silver;
	margin-top:20px;}
</style>
<script type="application/ecmascript">
function start(event)
	{event.dataTransfer.effectAllowed = 'copy';
	event.dataTransfer.addElement(document.querySelector('span'));}
function resetImage(event)
	{event.preventDefault()
	event.dataTransfer.addElement(document.querySelector('strong'));}
</script>
</head>
<body>
<p><a href="data:text/plain,1" ondragstart="start(event)">Drag me</a></p>
<p>Try to drag link above to the silver box. You should see word <span>PASS</span> not <strong>FAIL</strong> in feedback overlay all the time.</p>
<div ondragenter="event.preventDefault()" ondragover="resetImage(event)"/>
</body>
</html>