private function verifyExtensionFile()
    {
        $supported_image = array(
            'gif',
            'jpg',
            'jpeg',
            'png'
        );

        $fileName = $_SERVER['HTTP_X_FILE_NAME'];

        $ext = strtolower(pathinfo($fileName, PATHINFO_EXTENSION));
        if (in_array($ext, $supported_image)) {
            return true;
        }
        return false;
    }