// Here is how to post form data to self or to the same page &
// avoid the PHP_SELF exploits at the same time.
<form name="my_form" method="post"
action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>">
</form><?php if (!empty($_POST)): ?>
Welcome, <?php echo htmlspecialchars($_POST["name"]); ?>!<br>
Your email is <?php echo htmlspecialchars($_POST["email"]); ?>.<br>
<?php else: ?>
<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
Name: <input type="text" name="name"><br>
Email: <input type="text" name="email"><br>
<input type="submit">
</form>
<?php endif; ?>