<form action="<?php echo $_SERVER['PHP_SELF']; ?>">
//there is no reason to use this to submit form data to the same page
<form action="">
//will do the same thing<?php if (!empty($_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; ?>
<form name="form1" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>" >