why won't this page redirect? - php

Question

I'm having a problem with redirecting a page in php.
<?php
include '../include/dbfunctions.php';
$email = $password = "";
$err = "";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (isset($_POST['login']) && !empty($_POST['password'])) {
$email = trim($_POST['email']);
$password = trim($_POST['password']);
$link = get_db_connection();
if (mysqli_connect_errno()) {
die(" Something went wrong ! ");
}
$user_email = mysqli_real_escape_string($link, $email);
$user_password = mysqli_real_escape_string($link, $password);
$query = "SELECT username FROM user WHERE user_email = '$user_email' AND user_password = SHA1('$user_password') AND user_active = '1';";
$data = mysqli_query($link, $query);
if (mysqli_num_rows($data) == 1) {
$row = mysqli_fetch_array($data);
$username = $row['username'];
mysqli_close($link);
if (!empty($username)) {
header('location:http://www.xxxxxxxxxxxxxx.be/login/dashboard.php');
exit();
}
} else {
$err = "Invalid combination of e-mail and password";
echo $err;
}
} else {
}
}
?>
I can't figure it out. If i fill in an invalid password or email, i get the error message. But when they are correct, nothing happens.

Answer 1

if (!empty($username)) {
header('location:http://www.yoursite.be/login/dashboard.php?error=error in login please try agine');
exit();
}

Answer 2

if (!empty($username)) {
header('location:http://www.xxxxxxxxxxxxxx.be/login/dashboard.php');
exit();}
$username might be empty.