PHP Redirect

[Winterworks]

that's not my whole code.

<?php
if(isset($_POST['submit'])) {

$to = "mikemersereau@hotmail.com";
$subject = "Client Testimonial";
$name_field = $_POST['name'];
$email_field = $_POST['email'];
$message = $_POST['message'];
 
$body = "From: $name_field\n Email: $email_field\n Testimonial:\n $message";
 
echo "Data has been submitted to $to!";
mail($to, $subject, $body);

} else {

echo "error";

}
?>

I just need to know what to put where it says the "echo "Data has been...""