<body>

<script>
onload = function()
{
    // Submit the form in a timeout to make sure we generate a history entry.
    setTimeout(function() {document.getElementById('the-form').submitwithpost.click();}, 0);
}
</script>

<form id="the-form" method="POST" action="form-target.pl">
  <input name="the-input" value="input value goes here">
  <input type="submit" name="submitwithpost" value="Submit with POST"/><br>
</form>

</body>