<html>
<head>
<title>Page with POST form</title>
<script>
function SubmitForm() {
document.forms['doit'].submit();
}
</script>
</head>
<body>
<form id="doit" action="/downloads/image.jpg?allow-post-only" method="post">
<input type="Submit" value="Do It"/>
</form>
</body>
</html>