$this->warningMessage = $message;
        $this->warning = true;
    }
    public function setSuccess($message)
    {
        $this->successMessage = $message;
        $this->success = true;
    }
    public function unsetError()
    {
        $this->error = false;
    }
    public function unsetWarning()
    {
        $this->warning = false;
    }
    public function unsetSuccess()
    {
        $this->success = false;
    }
}
$alerts = new Alerts();
if (isset($_GET['error'])) {
    $alerts->setError($_GET['error']);
}
if (isset($_GET['warning'])) {
    $alerts->setWarning($_GET['warning']);
}
if (isset($_GET['success'])) {
    $alerts->setSuccess($_GET['success']);
}