<form id='login' action='loginconfirm.php' method='post'>
<fieldset >
<label style="font-family: gothamlight; color: white; font-size: 1em;"
class="loginform" for='username' >User:</label>
<input class="loginform" type='text' name='username' maxlength="50" />
<label style="font-family: gothamlight; color: white; font-size: 1em;"
class="loginform" for='password' >Passwort:</label>
<input class="loginform" type='password' name='password' maxlength="50"
/>
<input  type='submit' name='Submit' value='Login' />
</fieldset>
</form>

<?php
$username = mysqli_real_escape_string($_POST['username']);
$password = mysqli_real_escape_string($_POST['password']);
require 'datenbank.php';
$q = "SELECT * FROM users WHERE username = '$username'";
    $result = $mysqli->query($q) or die(mysqli_error());
if (mysqli_num_rows($result) == 1) {
    setcookie('authorized', 1, 0);
    header("Location: http://www.google.de");
}
else {
    header("Location: admin.php");
}
?>