loading blank page despite form action location upon error - php

Question

I am creating a simple form that a user submits and email. I am trying to pose an error if the form is blank or it's not a valid email and if successful, then reload the page with a success message.
When I submit blank it reloads the page without an error, and if I enter anything in ( valid or invalid email ) it reloads the page white, despite the form action being correct. I've been stuck on this and need help. Thanks.
<?php
require_once($_SERVER['DOCUMENT_ROOT'] . '/includes/system/init.php');
if(isset($_POST['submit'])) {
$email = $_POST['email'];
if(empty($_POST['email']) || !filter_var($email, FILTER_VALIDATE_EMAIL)) {
$error = "Please enter a valid email";
}else{
$success = true;
mysql_query("INSERT INTO survey
(email) VALUES('".$_POST['email']."' ) ")
or die(mysql_error());
}
}
?>
<div class="email-survey">
<?php if(isset($success)) { ?>
<div class="success">Thank You!</div>
<?php } ?>
<?php if(isset($error)) { ?>
<div class="error">
<?php echo $error; ?>
</div>
<?php } ?>
<form name="settings" action="/survey-confirm.php" method="post">
<input type="text" name="email" /> <br />
<input type="submit" name="submit" value="submit" />
</form>
</div>

Answer 1

<?php
function control($type, $text)
{
echo '<div class="'.$type.'">'.$text.'</div>';
}
require_once($_SERVER['DOCUMENT_ROOT'] . '/includes/system/init.php');
if(isset($_POST['submit'])) {
$email = $_POST['email'];
if(empty($_POST['email']) || !filter_var($email, FILTER_VALIDATE_EMAIL)) {
control('error', 'Type valid mail!');
}else{
control('success', 'All done!');
mysql_query("INSERT INTO survey
(email) VALUES('".$_POST['email']."' ) ")
or die(mysql_error());
}
}
else
{echo 'echo '<form name="settings" action="/survey-confirm.php" method="post">
<input type="text" name="email" /> <br />
<input type="submit" name="submit" value="submit" />
</form>
</div>';}
?>
This is small function named control, you can call this and put your custom div name and text to show user.
control('THIS IS DIV NAME','THIS IS MESSAGE FOR USER')