<html>
<head>
<title>Loading...</title>
</head>
<body onload="attachUnloadListener()">
<script>
function attachUnloadListener() {
window.addEventListener('unload', onUnload, false);
document.title = "set cookie on unload";
}
function onUnload() {
document.cookie = "onunloadCookie=foo";
}
</script>
<p>Navigate to another page to set cookie</p>
</body>
</html>