<form method="post" action="https://app.xxxx.com/main.php?moduleName=fm_subscribers&action=add_subscriber"> <input type="hidden" name="subscribers_list_hash" value="xxxxx" /> <label for="freshmail_email"> Email </label><br /><input type="text" name="xxxmail_email" id="xxxmail_email"><br /> <input type="submit" value="confirm"> </form>