function login(){
	global $db, $username, $errors;

	// grap form values
	$username = e($_POST['username']);
	$password = e($_POST['password']);

	// attempt login if no errors on form
	if (count($errors) == 0) {
		$query = "SELECT * FROM users WHERE username='$username' LIMIT 1";
		$results = mysqli_query($db, $query);
		$vypis = mysqli_fetch_array($results)
		if (password_verify ($vypis["password"], $password )){
				// user found logged
				// check if user is admin or user
				$logged_in_user = mysqli_fetch_assoc($results);
					if ($logged_in_user['user_type'] == 'admin') {

					$_SESSION['user'] = $logged_in_user;
					$_SESSION['success']  = "You are now logged in";
					header('location: index.php');
				}
				else {
					$_SESSION['user'] = $logged_in_user;
					$_SESSION['success']  = "You are now logged in";
					header('location: index.php');
					}
			}
		else {
			array_push($errors, "Wrong username/password combination");
			}
	}
}