php automatic redirect to a page : I am making a register form and when you succesfully filled in all the fields, it redirects to `thank_you_register.php`. But I want that after a few seconds, the `thank_you_register.php` page automatically redirects to another page. How do is do this?
The HTML code is this:

    <form class="register form" action="../app/controller/authController.php" method="POST">
				<div class="form-group">
					<select name="region" id="">
						<option value="Americas">Americas</option>
						<option value="Europe">Europe</option>
						<option value="Asia">Asia</option>
					</select>
				</div>
				<div class="form-group">
					<input type="text" name="first_name" id="" placeholder="First Name">
					<?php if(isset($_SESSION['first_name_error'] )) : ?>
						<span class="error"><?php echo $_SESSION['first_name_error']; ?></span>
					<?php unset($_SESSION['first_name_error']); endif; ?>
				</div>
				<div class="form-group">
					<input type="text" name="last_name" id="" placeholder="Last Name">
					<?php if(isset($_SESSION['last_name_error'] )) : ?>
						<span class="error"><?php echo $_SESSION['last_name_error']; ?></span>
					<?php unset($_SESSION['last_name_error']); endif; ?>
				</div>
				<div class="form-group">
					<input type="email" name="email" id="" placeholder="E-mail Address">
					<?php if(isset($_SESSION['email_error'] )) : ?>
						<span class="error"><?php echo $_SESSION['email_error']; ?></span>
					<?php unset($_SESSION['email_error']); endif; ?>
				</div>
				<div class="form-group">
					<input type="email" name="confirm_email" id="" placeholder="Confirm E-mail Address">
					<?php if(isset($_SESSION['confirm_email_error'])) : ?>
						<span class="error"><?php echo $_SESSION['confirm_email_error']; ?></span>
					<?php unset($_SESSION['confirm_email_error']); endif; ?>
				</div>
				<div class="form-group">
					<input type="password" name="password" id="" placeholder="Password">
					<?php if(isset($_SESSION['password_error'] )) : ?>
						<span class="error"><?php echo $_SESSION['password_error']; ?></span>
					<?php unset($_SESSION['password_error']); endif; ?>
				</div>
				<div class="form-group">
					<input type="password" name="confirm_password" id="" placeholder="Confirm Password">
					<?php if(isset($_SESSION['confirm_password_error'] )) : ?>
						<span class="error"><?php echo $_SESSION['confirm_password_error']; ?></span>
					<?php unset($_SESSION['confirm_password_error']); endif; ?>
				</div>
				<div class="form-group">
					<input type="text" name="age" id="" placeholder="Age">
					<?php if(isset($_SESSION['age_error'] )) : ?>
						<span class="error"><?php echo $_SESSION['age_error']; ?></span>
					<?php unset($_SESSION['age_error']); endif; ?>
				</div>
				<div class="form-group">
					<input type="submit" name="type" value="Register" class="register button">
				</div>
			</form>

And the PHP code of the form is this:

    if ($_POST['type'] == 'Register') {

		$i=0;
    	$names = array('first_name', 'last_name', 'email', 'confirm_email', 'password', 'confirm_password', 'age');
	    foreach($names as $field) {
	    	if (empty($_POST[$field])) {

	        	$_SESSION[$field.'_error'] = "Field cannot be empty!";
	        	$i++;
	    	}

	        else
	      	{
	          unset($_SESSION[$field.'_error']);
	          $user->redirect('register.php');
	      	}

	    }

	    if (sizeof($names) == $i) {
	    	$user->redirect('register.php');
	    }

	    if ($_POST['email'] != $_POST['confirm_email']) {
	    	$_SESSION['confirm_email_error'] = "E-mail Address does not match!";
	    	exit();
	    }

	    if ($_POST['password'] != $_POST['confirm_password']) {
	    	$_SESSION['confirm_password_error'] = "Password does not match!";
	    	exit();
	    }

		function add($region, $first_name, $last_name, $email, $confirm_email, $password, $confirm_password, $age) {
			var_dump($_POST);
			$database = Database::getInstance();
			$sql = "INSERT INTO `users`
					(`region`, `first_name`, `last_name`, `email`, `confirm_email`, `password`, `confirm_password`, `age`)
					VALUES (:region, :first_name, :last_name, :email, :confirm_email, :password, :confirm_password, :age)";

			$stmt = $database->pdo->prepare($sql);
			$stmt->bindParam(':region', $region);
			$stmt->bindParam(':first_name', $first_name);
			$stmt->bindParam(':last_name', $last_name);
			$stmt->bindParam(':email', $email);
			$stmt->bindParam(':confirm_email', $confirm_email);
			$stmt->bindParam(':password', $password);
			$stmt->bindParam(':confirm_password', $confirm_password);
			$stmt->bindParam(':age', $age);
			$stmt->execute();

		}

		$user->redirect('');

And the HTML code for the `thank_you_register` page is this:

    <?php require realpath(__DIR__ . '/header.php'); ?>

	<div class="main-content">
		<div class="messageBox">
			<div class="MB_head">
				<h2>Thank You!</h2>
			</div>
			<div class="MB_content">
				<p>You are registered.</p>
			</div>
		</div>
	</div>

<?php require realpath(__DIR__ . '/footer.php'); ?>