public static function getUserBrowser()
    {
        $user_agent = $_SERVER['HTTP_USER_AGENT'];
        $user_browser = 'unknown';

        if (false !== stripos($user_agent, 'MSIE') && false === stripos($user_agent, 'Opera')) {
            $user_browser = 'Internet Explorer';
        } elseif (false !== stripos($user_agent, 'Firefox')) {
            $user_browser = 'Mozilla Firefox';
        } elseif (false !== stripos($user_agent, 'Chrome')) {
            $user_browser = 'Google Chrome';
        } elseif (false !== stripos($user_agent, 'Safari')) {
            $user_browser = 'Apple Safari';
        } elseif (false !== stripos($user_agent, 'Opera')) {
            $user_browser = 'Opera';
        } elseif (false !== stripos($user_agent, 'Netscape')) {
            $user_browser = 'Netscape';
        }

        return $user_browser;
    }