List of ways to get $idresult back to website.htm

PHP
1

List of ways to get $idresult back to website.htm

website.htm

<form name="myform" action="website.php" method="post">
     <input name="Hidden1" type="hidden" value="??" />
</form>

website.php

<?php
    $id = filter_input(INPUT_POST, "Hidden1");
        //do work on $id to get $idresult
        //list of ways to get $idresult back to Hidden1 in website.htm
        return header("Location: http://www.mysite.com/website.htm");
?>