Yes it can be done... you just aren't maintaining your recordset state over the form submit. Since your recordset is filtered by a url parameter, you have to make sure to pass that url parameter through when you resubmit the page. Just update your form action from:
action="<?php echo $_SERVER["PHP_SELF"]; ?>"
to:
action="<?php echo $_SERVER["PHP_SELF"]; ?>?userID=<?php echo($_GET['userID']); ?>"